A Zoogeographic Study and the Taxonomy of the Xenodontine

Colubrid Snakes

by

Janann Jenner

A dissertation in the Department of Biology submitted to

the Faculty of the Graduate School of Arts and Science in

partial fulfillment of the requirements for the degree of

Doctor of Philosophy at New York University.

May, 1981

Approved

Herndon G. Dowling Professor Department of Biology

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Copyright (c) 1981, Janann Jenner

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNOWLEDGEMENTS

The author gives special thanks to:

- Dr. Herndon G. Dowling, sponsor and teacher.

His generosity, thoughtfulness, and patient support

during the preparation of this thesis has created a

debt that can never be adequately repaid.

- John Fuchs and Itschak Gilboa, City University

Computer Center, who designed the computer software

necessary to produce the computer maps.

- George Foley, Dr. Charles W. Myers, and Margaret

Shaw, Department of Herpetology, American Museum of

Natural History, who allowed the use of the herpe-

tological literature citation cross-index.

- Frances Irish, Dr. Roy McDiarmid, and Dr. George

Zug, Department of Herpetology, United States National

Museum, who allowed the use of specimens and library.

- The Department of Biology of New York University

for financial support.

- The New York University Computer Center for fin­

ancial support.

- Herpetological Information Search Systems (HISS)

for use of hemipenis drawings.

- Dr. Irving Brick, Dr. Calvin Heusser, Dr. Joseph

LoBue, Dr. Janis Roze, Dr. Fleur Strand, members of my

doctoral committee, for their helpful criticisms.

- iii -

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. - Karen Anderson, Barbara Pytel, Lisa Levinson,

and Esther Indelman, herpetology graduate students, who

made suggestions during the final preparation of this

thesis.

- Dr. Barbara Brummer and Tom Brummer who encouraged

me that someday this thesis would be finished and pulled

me back from the window ledge many times.

- Richard Carter, William Elek, Miesje Jolley,

Allerton Kilbome, Verna Koons, Lanette McAndrews, James

McAndrews, Melanie Perish, Bernie Weinstein, and Dr. Lou

Wise who were never too busy to listen to my woes and

offer encouragement.

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ABSTRACT

Author: Janann Jenner

Title: A Zoogeographic Study and the Taxonomy of the

Xenodontine Colubrid Snakes

Research Advisor: Herndon G. Dowling, Professor of

Biology, New York University.

Morphological and geographic analysis of the xeno­

dontine colubrid snakes demonstrated that previous tribal

criteria as well as tribal allocations were erroneous. Two

previous tribes are not accepted. Four new tribes are des­

cribed.

Four genera (Scolecophis, Simophis, Tantilla, and Tri-

morphodon) were transferred to the Subfamily Colubrinae.

Genera with flounced hemipenes (Conophis, Ialtris, Pseudo-

eryx and some species of Atractus and of Coniophanes) as

well as those genera with inadequate hemipenial descrip­

tions (Ditaxodon, Elapomojus, Hydromorphus, Lioheterophis,

Parapostolepis, Paraptychophis, Platynion, and Tantillita)

cannot be properly assigned to xenodontine tribes.

The remaining xenodontine genera are allocated to

seven tribes. Each tribe has a distinctive hemipenial con­

figuration and a cohesive geographic range. Tribal criteria

and allocations are as follows:

Tribe Alsophiini is defined by possession of a bilobed,

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. semicapitate hemipenis with proximal spines, distal caly­

ces, and forked sulcus. Its geographic distribution is

centered in Hispaniola. Alsophis, Antillophis, Arrhyton,

Farancia, Helicops, Heterodon, Hydrodynastes, Hypsirhynchus,

Uromacer, and Uromacerina are allocated to Tribe Alsophiini.

Tribe Diaphorolepini is defined by possession of an

entirely spinose, noncapitate hemipenis with a forked sul­

cus. Its geographic distribution is centered in southern

South America. Atractus, Chersodromus, Crisantophis, Dia-

phorolepis, Elapomorphus, Enulius, Gomesophis, Pseudotom-

odon. Ptvchophis. and Sordellina are allocated to Tribe

Diaphorolepini.

Tribe Dipsadini is defined by possession of a fully

capitate hemipenis wit; proximal spines and a forked sul­

cus. Its geographic distribution is centered in Central

America. Adelphicos, Coniophanes, Cryophis , Dipsas, Geo-

phis , Ninia, Pliocercus, Rhadinaea, Sibon, Sibynomorphus,

Tretanorhinus, Trimetopon, and Tropidodipsas are allocated

to Tribe Dipsadini.

Tribe Leptodeirini is defined by possession of a fully

capitate, single or bilobed hemipenis with a simple sul­

cus. Its geographic distribution is centered on the north­

ern Pacific coast of Mexico. Eridiphas, Hypsiglena, Iman-

todes, and Leptodeira are allocated to Tribe Leptodeirini.

Tribe Philodryini is defined by possession of a

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. bilobed or single, noncapitate hemipenis with a forked

sulcus, proximal spines, and distal calyces. Its geo­

graphic distribution is centered in southern South Amer­

ica. Amastridium, Apostolepis, Calamodontophis, Carphophis

Contia, Diadophis, Hydrops, Manolepis, Nothopsis, Philo-

dryas, Pseudablabes, Synophis, Tachymenis, Thamnodynastes,

Tomodon, and Xenopholis are allocated to Tribe Philodryini.

Tribe Pseudoboini is defined by possession of a bi­

lobed, bicapitate hemipenis with a forked sulcus. Its dis­

tribution is centered in Matto Grosso, Brazil,and adjacent

Bolivia. Clelia, Drepanoides, Oxyrhopus, Phimophis, Pse­

udoboa, Rhachidelus, Saphenophis, Siphlophis, Tripanurgos.

and Tropidodryas are allocated to Tribe Pseudoboini.

Subfamily Xenodontinae is partitioned into northern

and southern units. Alsophiini, Dipsadini, and Leptodeir­

ini are northern tribes, while Diaphorolepini, Philodry­

ini, Pseudoboini, and Xenodontini are southern tribes. Geo­

graphic patterns, latitudinal distributions, maxillary den­

tition, length of maxilla, and mode of scale row reduc­

tion support the existence of northern and southern xenodon

tines.

It is hypothesized that Subfamily Xenodontinae orig­

inated from a lycodontine ancestor which had an entirely

spinose hemipenis with a forked sulcus. Tribe Diaphorolep­

ini retains this ancestral hemipenial configuration. The

ancestors of Tribe Philodryini developed calyces on other-

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. wise spinose hemipenes. Calyces were restricted to the

apices of the lobes of the hemipenes of Tribe Pseudoboini.

Disked hemipenes developed in the Xenodontini. The north­

ern tribes originated from a philodryine ancestor and spread

from northern South America to the Lesser and Greater Ant­

illes and northward into North America. Alsophines iso­

lated in Middle America developed the capitate hemipenis

and became dipsadines. Dipsadines which lost one fork of

the sulcus became the leptodeirines. Dipsadines and lepto-

deirines dispersed to South America after the isthmian con­

nection was established in the late Pliocene.

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. CONTENTS

Page

Acknowledgements ------iii

Abstract ------v

List of Tables ------xiii

List of F i g u r e s ------xvi

I. Background------1

A. Colubrid Snake Taxonomy ------1

B. Historical Review ------2

1. Cope's Contributions ------2

2. D u n n ------3

3. Underwood ------3

4. D o w l i n g ------8

C. Subfamily Xenodontinae ------8

D. Hemipenes ------11

E. Xenodontine Hemipenes ------13

F. Other Xenodontine Characters ------15

G. Rationale for Present W o r k ------17

H. Importance of Zoogeography to Systematics------18

I. Zoogeography of Xenodontine Tribes ------19

1. Factors Influencing Xenodontine

Distributions ------19

2. Physiography of Mexico and Central America -- 20

3. Physiography of South America ------22

4. Plate Tectonics ------25

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 5. Continental Drift: The Global History -- 27

6. Tectonics and Drift in the Western

Hemisphere ------29

7. Conclusions from Paleogeography------33

8. Effects of Continental Drift ------34

9. Temperature and Precipitation------35

10. Climate ------36

11. Climatic Regimes ------38

12. History of Climatic Change ------43

13. Vegetation ------44

14. Biotic Provinces ------53

15. Importance of the Genus to

Zoogeographic Analysis ------57

II. Materials and Methods ------59

A. Map Construction------59

B. Map Analysis ------61

C. Morphological Information and Erection

of New Tribes ------62

D. Explanation of Generic Summaries ------68

III. Discussion------217

A. Genera Deleted from Tribal Allocations ------217

1. Genera Transferred to Subfamily Colubrinae 217

2. Genera With Flounced Hemipenes ------218

3. Genera With Inadequate D a t a ------218

4. Summary of Genera Deleted From Tribal

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Allocations ------220

B. Tribal Allocations ------220

1. Tribe Alsophiini ------223

a. E c o l o g y ------223

b. Morphology ------225

c. Discussion ------228

d. Geography ------232

e. Discussion and Relationships ------234

2. Tribe Diaphorolepini ------236

a. E c o l o g y ------236

b. Morphology ------239

c. Geography ------244

d. Discussion and Relationships ------246

3. Tribe Dipsadini ------248

a. E c o l o g y ------248

b. Morphology ------251

c. Geography ------258

d. Discussion and Relationships ------258

e. S u m m a r y ------261

4. Tribe Leptodeirini ------262

a. E c o l o g y ------262

b. Morphology ------262

c. Geography and Relationships ------267

d. S u m m a r y ------267

5. Tribe Philodryini ------270

a. E c o l o g y ------270

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. b. Morphology ------270

c. Geography ------276

d. S u m m a r y ------280

6. Tribe Pseudoboini ------282

a. E c o l o g y ------282

b. Morphology ------286

c. Geography ------289

d. Discussion and Relationships ------292

7. Tribe Xenodontini ------294

a. E c o l o g y ------294

b. Morphology ------296

c. Geography and Discussion------302

8. Northern and Southern Xenodontine Tribes - 305

9. History of the Southern and Northern

T r i b e s ------...... 311

10. Revised Taxonomy of Subfamily Xenodontinae 313

IV. Summary------315

V. References ------321

VI. Biographical Sketch: Janann Jenner ------355

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. LIST OF TABLES

Page

1. Classification of Colubrid Snakes (Cope, 1895) - 4

2. Classification of Colubrid Snakes (Dunn, 1928) - 5

3. Genera of the Ophiinae (Dunn, 1928) ------6

4. Classification of Colubrid Snakes

(Underwood, 1967) ------9

5. Classification of Colubrid Snakes

(Dowling, 1978) ------^

6. Subfamily Xenodontinae (Dowling, 1978) ------16

7. Hemipenes of Subfamily Xenodontinae ------221

8. Tribe Alsophiini - Ecology ------224

9. Tribe Alsophiini - Morphological Information — 226

10. Tribe Alsophiini - Head Scutes ------229

11. Tribe Alsophiini - Maxillary Dentition ------230

12. Tribe Alsophiini - Hemipenes------231

13. Tribe Alsophiini - Latitudinal Distribution -- 235

14. Tribe Diaphorolepini - Hemipenes ------237

15. Tribe Diaphorolepini - Ecology ------238

16. Tribe Diaphorolepini - Maxillary Dentition --- 240

17. Tribe Diaphorolepini - Morphological

Information------242

18. Tribe Diaphorolepini - Head Scutes ------243

19. Tribe Diaphorolepini - Latitudinal Distribution 247

20. Tribe Dipsadini - Hemipenes------249

21. Tribe Dipsadini - Ecology ------250

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 22. Tribe Dipsadini - Morphological Information --- 252

23. Tribe Dipsadini - Head Scutes ------254

24. Tribe Dipsadini - Maxillary Dentition ------256

25. Tribe Dipsadini - Latitudinal Distribution ---- 260

26. Tribe Leptodeirini - Hemipenes ------263

27. Tribe Leptodeirini - Ecology ------263

28. Tribe Leptodeirini - Morphological Information 264

29. Tribe Leptodeirini - Head Scutes ------266

30. Tribe Leptodeirini - Maxillary Dentition ------266

31. Tribe Leptodeirini - Latitudinal Distribution - 269

32. Tribe Philodryini - Hemipenes------271

33. Tribe Philodryini - Ecology ------272

34. Tribe Philodryini - Morphological Information - 273

35. Tribe Philodryini - Maxillary Dentition ------277

36. Tribe Philodryini - Head Scutes ------278

37. Tribe Philodryini - Latitudinal Distribution -- 281

38. Tribe Pseudoboini - Hemipenes ------283

39. Tribe Pseudoboini - Ecology ------284

40. Tribe Pseudoboini - Maxillary Dentition ------285

41. Tribe Pseudoboini - Morphological

Characteristics ------287

42. Tribe Pseudoboini - Head Scutes ------290

43. Tribe Pseudoboini - Latitudinal Distribution -- 293

44. Tribe Xenodontini - Ecology ------295

45. Tribe Xenodontini - Morphological

Characteristics ------297

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 46. Tribe Xenodontini - Head Scutes ------298

47. Tribe Xenodontini - Maxillary Dentition ------299

48. Tribe Xenodontini - Hemipenes ------301

49. Tribe Xenodontini - Latitudinal Distribution ---- 304

50. Subfamily Xenodontinae - Maxillary Dentition -- 307

51. Northern and Southern Tribes: Fangs vs No Fangs 308

52. Northern and Southern Tribes: No. of Teeth ---- 308

53. Northern and Southern Tribes: Length of Maxilla 310

54. Subfamily Xenodontinae - Revised Taxonomy ------314

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. LIST OF FIGURES

Page

1. Features of Hemipenial Morphology ------12

2. Hemipenial, Maxillary, and Vertebral Character­

istics of Xenodontine Tribes ------14

3. Topography of Mexico and Central America ------21

4. Elevations of Middle America ------23

5. Elevations in South America ------24

6. Lithospheric Plates in the Western Hemisphere -- 26

7. Climatic Regions in the Western Hemisphere ---- 37

8. Humid Tropical Assemblage in Central America -- 49

9. Arid Tropical Herpetofaunal Assemblage in

Central America ------50

10. Humid Montane Herpetofaunal Assemblage in

Central America ------51

11. Arid Montane Herpetofaunal Assemblage in

Central America ------54

12. High Montane Herpetofaunal Assemblage in

Central America ------55

13. Biotic Provinces of Mexico ------56

14. Geographic Distribution of Adelphicos ------71

15. Distribution of Species of Alsophis ------72

16. Distribution of Species of Alsophis ------73

17. Distribution of Species of Al s o p h i s ------73

18. Distribution of Amastridium veliferum ------74

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 19. Geographic Distribution of Species

of Antillophis ------75

20. Geographic Distribution of Species

of Apostolepis ------76

21. Geographic Distribution of Species

of Apostolepis ------77

22. Geographic Distribution of Species of

of Apostolepis ------77

23. Geographic Distribution of Species of Arrhyton - 78

24. Distribution of the Atractus badius Group ------81

25. Distribution of the Atractus elaps Group ------82

26. Distribution of Atractus trilineatus ------83

27. Distribution of Members of the

Atractus trilineatus Group ------83

28. Distribution of Members of the

Atractus trilineatus Group------84

29. Distribution of Members of the

Atractus trilineatus Group------84

30. Distribution of Species of Atractus ------85

31. Distribution of Species of Atractus ------86

32. Distribution of Species of Atractus ------86

33. Distribution of Species of Atractus ------87

34. Distribution of Species of Atractus ------88

35. Distribution of Species of Atractus ------88

36. Geographic Range of Calamodontophis paucidens -- 89

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 37. Geographic Range of Carphophis amoenus ------90

38. Geographic Range of Species of Chersodromus ---- 91

39. Geographic Distributions of Species of Clelia -- 92

40. Geographic Distribution of Clelia equatoriana -- 93

41. Geographic Distribution of Species of Clelia -- 93

42. Geographic Distribution of the Coniophanes

bipunctatus Group ------95

43. Geographic Distribution of the Coniophanes

imperialis Group and Coniophanes lateritius ---- 96

44. Distribution of Species of Coniophanes ------97

45. Distribution of Species of Coniophanes ------97

46. Geographic Distribution of Species of Conophis - 98

47. Geographic Distribution of Contia tenuis ------99

48. Geographic Distribution of Crisantophis

nevermanni------100

49. Geographic Distribution of Cryophis hallbergi -- 101

50. Geographic Distribution of Darlingtonia haetiana 102

51. Geographic Distribution of Diadophis punctatus - 103

52. Geographic Distribution of Diadophis dugesii -- 103

53. Geographic Distribution of Diaphorolepis ------104

54. Geographic Distribution of the Dipsas

articulata Group ------107

55. Geographic Distribution of Members of the

Dipsas articulata Group ------107

56. Geographic Distribution of Dipsas gaigeae ------108

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 57. Geographic Distribution of Members of

the Dipsas catesbvi Group ------108

58. Geographic Distribution of the

Dipsas indica Group ------109

59. Geographic Distribution of the

Dipsas oreas Croup ------109

60. Geogrpahic Distribution of the

Dipsas polylepis Group ------110

61. Geographic Distribution of the

Dipsas pratti Group ------110

62. Geographic Distribution of the

Dipsas variegata Group ------111

63. Geographic Distribution of Dipsas variegata --- 111

64. Geographic Distribution of Dipsas sanniolus --- 112

65. Geographic Distribution of Dipsas elegans ------112

66. Geographic Distribution of Ditaxodon taeniatus - 113

67. Geographic Distribution of Drepanoides anomalus 114

68. Geographic Distribution of Species of the

Dromicus melanotus Group ------115

69. Geographic Distribution of Species of Dromicus - 115

70. Distribution of Species of Dromicus ------116

71. Distribution of Dromicus almadensis------116

72. Geographic Distribution of Elapomojus dimidiatus 117

73. Geographic Distribution of Species of

Elapomorphus------118

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 74. Geographic Distribution of Species of

Elapomorphus ------<------118

75. Geographic Distribution of Species of Enulius -- 119

76. Geographic Distribution of Eridiphas slevini --- 120

77. Geographic Distribution of Species of

Erythrolamprus ------121

78. Geographic Distribution of Species of

Erythrolamprus ------121

79. Geographic Distribution of Species of Farancia - 122

80. Geographic Distribution of

Geophis championi Group ------124

81. Geographic Distribution of

Geophis omiltemanus Group ------125

82. Geographic Distribution of

Geophis latifrontalis Group ------125

83. Geographic Distribution of

Geophis semidoliatus Group ------126

84. Geographic Distribution of

Geophis chalybeus Group------126

85. Geographic Distribution of Members of

Geophis sieboldi Group------127

86. Geographic Distribution of Members of

Geophis sieboldi Group------127

87. Geographic Distribution of Geophis dubius Group 128

88. Geographic Distribution of Geophis dubius Group 128

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 89. Geographic Distribution of Geophis Species

Not Assigned to a Subgeneric Group ------129

90. Geographic Distribution of Geophis Species

Not Assigned to a Subgeneric Group ------129

91. Geographic Distribution of Gomesophis

brasiliensis ------130

92. Geographic Distribution of Helicops leopardinus

and Helicops trivittatus ------131

93. Geographic Distribution of Species of Helicops - 132

94. Geographic Distribution of Species of Helicops - 132

95. Geogrpahic Distribution of Species of Heterodon 133

96. Geographic Distribution of Species

of Hydrodynastes------134

97. Geographic Distribution of Species

of Hydromorphus ------135

98. Geographic Distribution of Species of Hydrops -- 136

99. Geographic Distribution of Species

of Hypsiglena ------137

100. Geographic Distribution of Hypsirhynchus ferox 138

101. Geographic Distribution of Species of Ialtris - 139

102. Geographic Distribtuion of Species of Imantodes 140

103. Geographic Distribution of Imantodes lentiferus 141

104. Geographic Distribution of Imantodes cenchoa -- 141

105. Geographic Distribution of Species

of Leimadophis ------142

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 106. Geographic Distribution of Species

of Leimadophis ------142

107. Geographic Distribution of Species

of Leimadophis ------143

108. Geographic Distribution of Species 143 of Leimadophis ------

109. Distribution of Leptodeira punctata------145

110. Distribution of the Leptodeira

nigrofasciata Group ------145

111. Distribution of Species of the

Leptodeira annulata Group ------146

112. Distribution of Species of the

Leptodeira annulata Group ------146

113. Distribution of Species of the

Leptodeira septentrionalis Group ------147

114. Distribtuion of Species of the

Leptodeira septentrionalis Group ------147

115. Geographic Distribution of Lioheterophis

i h e r i n g i ------148

116. Geographic Distribution of Species of Liophis - 149

117. Geographic Distribution of Species of Liophis - 149

118. Geographic Distribution of Species of Liophis - 150

119. Geographic Distribution of Species of Liophis - 150

120. Geographic Distribution of Liophis undulatus -- 151

121. Geographic Distribution of Species of Lygophis 152

122. Geographic Distribution of Species of

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Lystrophis------153

123. Geographic Distribution of Manolepis putnami -- 154

124. Geographic Distribution of Species of Ninia --- 156

125. Geographic Distribution of Ninia diademata ---- 156

126. Geographic Distribution of Ninia sebae ------157

127. Geographic Distribution of Species of Ninia --- 157

128. Geographic Distribution of Nothopsis rugosus -- 158

129. Geographic Distribution of Species of

Oxyrh o p u s------159

130. Geographic Distribution of Species of

O x y r h o p u s ------159

131. Geographic Distribution of Species of

Oxyrhopus ------160

132. Geographic Distribution of

Parapostolepis polylepis ------161

133. Geographic Distribution of

Paraptychophis meyeri ------162

134. Geographic Distribution of Species of

Philodryas------163

135. Geographic Distribution of Species of

Philodryas ------163

136. Geographic Distribution of Species of

Philodryas------164

13 7. Geographic Distribution of Species of

Philodryas ------164

138. Geographic Distribution of Species of Phimophis 165

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 139. Geographic Distribution of Phimophis guianensis 165

140. Geographic Distribution of Platynion lividum -- 166

141. Geographic Distribution of Species

of Pliocercus------167

142. Geographic Distribution of Species

of Pliocercus------167

143. Geographic Distribution of Species of

of Pliocercus------168

144. Geographic Distribution of Pseudablabes

a g a s s i z i ------169

145. Geographic Distribution of Species of Pseudoboa 170

146. Geographic Distribution of

Pseudoeryx plicatilis ------171

147. Geographic Distribution of

Pseudotomodon trigonatus------172

148. Geographic Distribution of

Ptychophis flavovirgatus ------173

149. Geographic Distribution of Rhachidelus brazili 174

150. Geographic Distribution of Rhadinaea flavilata 176

151. Geographic Distribution of Rhadinaea laureata - 176

152. Geographic Distribution of the

Rhadinaea decorata Species Group ------177

153. Geographic Distribution of the

Rhadinaea decorata Species Group ------177

154. Geographic Distribution of the

Rhadinaea taeniata Species Group ------178

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 155. Geographic Distribution of the

Rhadinaea godmani Species Group ------179

156. Geographic Distribution of the

Rhadinaea godmani Species Group ------179

157. Geographic Distribution of the

Rhadinaea calligaster Species Group ------180

158. Geographic Distribution of the

Rhadinaea vermiculaticeps Species Group ------180

159. Geographic Distribution of the

Rhadinaea lateristriga Species Group ------181

160. Geographic Distribution of the

Rhadinaea brevirostris Species Group ------182

161. Geographic Distribution of the

Rhadinaea brevirostris Species Group ------182

162. Geographic Distribution of Species of

Saphenophis ------183

163. Geographic Distribution of Scolecophis

atrocinctus ------184

164. Geographic Distribution of Species of Sibon --- 185

165. Geographic Distribution of Species of Sibon --- 185

166. Geographic Distribution of Species of Sibon --- 186

167. Geographic Distribution of

Species of Sibynomorphus------187

168. Geographic Distribution of Species of Simophis 188

169. Geographic Distribution of Species of

Siphlophis ------189

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 170. Geographic Distribution of Sordellina punctata 1SJ

171. Geographic Distribution of Species of Synophis 191

172. Geographic Distribution of

Species of Tachymenis ------192

173. Geographic Distribution of

Tachymenis peruviana ------192

174. Geographic Distribution of

Tantalophis discolor ------193

175. Geographic Distribution of Species of Tantilla 195

176. Geographic Distribution of Species of Tantilla 196

177. Geographic Distribution of Species of Tantilla 196

178. Geographic Distribution of Species of Tantilla 197

179. Geographic Distribution of Species of Tantilla 197

180. Geographic Distribution of Species of Tantilla 198

181. Geographic Distribution of Species of Tantilla 199

182. Geographic Distribution of Species of Tantilla 199

183. Geographic Distribution of

Tantilla melanocephala ------200

184. Geographic Distribution of Tantilla utahensis - 200

185. Geographic Distribution of Species of

Tantillita------201

186. Geographic Distribution of Species

of Thamnodynastes ------202

187. Geographic Distribution of Species of Tomodon - 203

188. Geographic Distribution of

Species of Tretanorhinus ------205

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 189. Geographic Distribution of

Tretanorhinus mocquardi ------205

190. Geographic Distribution of Species of

of Trimetopon------206

191. Geographic Distribution of Species

of Trimorphodon------207

192. Geographic Distribution of Species

of Trimorphodon------207

193. Geographic Distribution of

Tripanurgos compressus ------208

194. Geographic Distribution of

Species of Tropidodipsas ------209

195. Geographic Distribution of

Species of Tropidodipsas ------209

196. Geographic Distribution of

Species of Tropidodipsas ------210

197. Geographic Distribution of Species

of Umbrivaga ------211

198. Geographic Distribution of Species of Uromacer 212

199. Geographic Distribution of

Uromacerina ricardinii ------213

200. Geographic Distribution of Waglerophis meremii- 214

201. Geographic Distribution of Species of Xenodon - 215

202. Geographic Distribution of Species of Xenodon - 215

203. Geographic Distribution of Species of

Xenopholis------216

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 204. Geographic Distribution of Tribe Alsophiini 233

2C5. Geographic Distribution of

Tribe Diaphorolepini------245

206. Geographic Distribution of Tribe Dipsadini ---- 259

207. Geographic Distribution of

Tribe Leptodeirini------268

208. Geographic Range of Tribe Philodryini ------279

209. Geographic Range of Tribe Pseudoboini ------291

210. Geographic Range of Tribe Xenodontini ------303

211. Latitudinal Distribution of Subfamily

Xenodontinae ------306

- xxviii -

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A. COLUBRID SNAKE TAXONOMY

The cosmopolitan family Colubridae, with 291 genera

and more than 1,500 species, contains the great majority

of the harmless or slightly venomous snakes (Dowling and

Duellman, 1978). Colubrid snakes are mainly recognized

by the absence of morphological features (Dowling, 1959).

All colubrid snakes lack such plesiomorphic characters

as premaxillary teeth, postfrontal bones, coronoid bones,

pelvic vestiges, and functional left lung. They have

reduced body musculature, non-segmental arteries, a single

internal carotid, a Y- or U-shaped hyoid with long, par­

allel cornua, uniform head scutellation, and an elongate

maxillary which lacks anterior fangs (Dowling and Duell­

man, 1978) . The xenodontines, the subject of the present

work, are a subfamily of Neotropical colubrid snakes.

Because no pertinent fossil record exists, ophidian

taxonomists must base their judgements upon the morph­

ology of living representatives. Although taxonomists

agree upon typical colubrid morphological characters,

interrelationships of the family have eluded herpetolog­

ists since the 1800's and still pose many unsolved tax­

onomic problems. Duellman (1965) has described the cur­

rent state of colubrid systematics as "chaotic." A his­

torical review of colubrid taxonomy will explain the

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. manner in which this confusion has evolved.

B. HISTORICAL REVIEW

1. Cope * s Contributions

The colubrid taxonomic tangle began to be unraveled

in the late 1800's, when Edward D. Cope presented a class

ification of snakes which, for the first time, incorp­

orated features of the hemipenes and lung (1893, 1894,

1895). Whereas earlier taxonomists such as Daudin (1803)

and Dumeril, Bibron, and Dumeril (1854) had based their

taxonomic judgements upon dentition and body shape (Sch­

midt, 1955), Cope rejected these characters as unreliable

Using new morphological characters such as hemipenes,

osteology, and lung structure, Cope (1895) divided his

Suborder Colubroidea into five divisions:

Peropoda: -boas and pythons: pelvic vestiges.

Aglyphodonta: -nonvenomous snakes, no pelvic vestiges or grooved teeth.

Glyphodonta: -nonvenomous snakes, no pelvic vestiges, but with posterior grooved teeth.

Proteroglypha: -venomous land snakes with anterior fangs.

Platycerca: -venomous sea snakes.

Thus, Cope placed what are presently recognized as colu-

brids into two superfamilies: Aglyphodonta and Glypho­

donta. These superfamilies were differentiated by pres­

ence or absence of posterior maxillary grooved teeth.

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Cope scattered the 38 known xenodontine genera among

seven subfamilies. His classification of the Family

Colubridae is set forth in Table 1.

2. Dunn

Dunn (1928b) rejected Cope's colubrid classification

and supergeneric groupings, damning them as "completely

unnatural assemblages." Dunn objected to Cope's reliance

upon tooth grooves which might not be evident under all

magnifications, and to Cope's all • *:ion of what appeared

to be pairs of species to widely differing groups. In­

stead, Dunn proposed four colubrid subfamilies based on

features of hemipenis, vertebrae, and skull. He comment­

ed that his new allocations had the extra bonus of making

geographic sense. Dunn's simpler colubrid classification

is set forth in Table 2. It groups the Xenodontinae into

one subfamily, Ophiinae, on the basis of the character­

istic forked sulcus spermaticus of the hemipenis. In

effect, Dunn's classification redefined the xenodontines

and added more genera to the subfamily (Table 3).

3. Underwood

In 1967 Underwood proposed a radically different

classification of snakes based upon arterial system,

skull bones, visual cells, maxillary teeth, labial glands,

hypapophyses, renal arteries, hemipenis, lungs, and scale

organs. Underwood grouped the colubrid snakes (sensu

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TABLE 1. CLASSIFICATION OF COLUBRID SNAKES (COPE, 1895)

Superfamily AGLYPHODONTA (no pelvic vestiges, no grooved teeth)

Family COLUBRIDAE Number of Genera mily Calamarinae 6 (0) Xenodontinae 4 (3) Dromicinae 22 (17-18) Leptognathinae 3 (2) Colubrinae 39 (3-4) Anoplophallinae 1 (0) Lycodontinae / 9 (0) Natricinae 12 (0)

GLYPHODONTA (no pelvic vestiges, grooved posterior teeth)

Family DIPSADIDAE

Subfamily Erythrolamprinae 2 (2) Scytalinae 11 (8) Dipsadinae 18 (4) Homalopsinae 6 (0)

(NOTE: Numbers in parentheses indicate number of genera now allocated to the subfamily Xenodontinae; underline shows subfamilies with xenodontine allocations.)

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TABLE 2. CLASSIFICATION OF AMERICAN COLUBRID SNAKES (DUNN, 1928b)

Subfamily OPHIINAE*: Sulcus spermaticus forked.

COLUBRINAE: Sulcus spermaticus single. No posterior hypapophyses.

SIBYNOPHIINAE: Posterior hypapophyses pre­ sent. Dentary free posteri­ orly. Hemipenis calyculate distally.

NATRICINAE: Hypapophyses short. Dentary not free posteriorly. Hemi­ penis not calyculate distal ly. Hemipenis spinose.

*NOTE: Ophiinae = Xenodontinae, Bonaparte, 1848. D u n n misinterpreted the priority of the name, Ophis.

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TABLE 3. CURRENT TRIBAL ALLOCATIONS OF GENERA OF THE

OPHIINAE (DUNN, 1928b)

Abastor (= F a r a n c i a ) ______A Acanthophallus (= Xenodon) ______Alsophis______A Amastridium N Apostolepis______A Arrhyton______A Atractus______A Carphophis _____ D Chersodromus______N Clelia______A Coniophanes _____ D Conophis______A Cyclagras (= Hydrodynastes) A Diadophis______D Diamedes (= Pseudoeryx) A Dipsas Drepanoides Dr omi cus______XX.X. Echinanthera (= Leimadophis) Erythrolamprus______Erythroxyrhopus (= Oxyrhopus) Farancia Geophis______D Heterodon______A Hydrocalamus (= C o n i o p h a n e s ) _____ D Hydrops ______H Hyp s irhynchus A Helicops______H Ialtris A X

Leimadophis______XXX , Leptocalamus ( = Enulius) H Liophis______Lygophis______Lys trophTs Manolepis __ D Mesopeltis (= Sibon) D Ninia N Ophis (= Xenodon) X Philodryas A Petalognathus (- S i b o n ) _____ D Pseudablabes______A Pseudoboa A Pseudopareas (= Sibynomorphus) Rhinostoma (= Lystrophis) j Siphlophis_ _ Tachymenis" Thamnodyna s t e s_

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TABLE 3 (Cont.)

T o m o d o n ______H Tretanorhinus D Tropidodipsas______A Uromacer ^ ______A Urotheca (= R h a d i n a e a ) _____ D

Probably Ophiinae

Atractopsis (= Atractus)______A Barbourina (= Clelia)______A Diaphorolepis ______N Elapomoius (= Elapomojus) ~ K Geatractus (= Tropidodipsas)_____ A Heterorhachis (= Dipsas)______D Lejosophis (= Hydrodynastes)_____ A Neopareas (= Dipsas)______D Paraoxyrhopus______N Platynion______A Pseudotomodon H Rachidelus ______A Rhinodryas (= Philodryas)______A Sordellina ____ D Sympholis______H Synophis______N Trypanurgos (= Tripanurgos) A

(NOTE: Letters indicate present tribal allocations A = Alsophiini D = Dipsadini H = Hydropsini N = Nothopsini X = Xenodontini Dowling and Duellman, 1978)

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latu) as set forth in Table 4. Although Underwood's at­

tempt to use a wide spectrum of morphological characters

is laudable, his criteria are inconsistently used. Thus,

rather than clarifying colubrid systematics, his shotgun

approach confused it even further.

4. Dowling

Dowling has presented the most comprehensive

view of the relationships of the colubrid snakes (1975,

Dowling and Duellman, 1978). His taxonomy has been des­

cribed as "beautifully simple, resulting in geographically

discrete groups" (Laurent, 1980). Dowling recognizes

four subfamilies based on morphological features, but

he especially relies upon the morphology of the hemi­

penis, the male copulatory organ. Dowling’s subfamilies

are:

Xenodontinae (93 genera, 557 species) Neotropical

snakes.

Lycodontinae (74 genera, 285 species) Old World

snakes.

Colubrinae (74 genera, 439 species) Typical harm­

less snakes.

Natricinae (45 genera, 218 species) Water snakes.

Each subfamily has a number of tribes, set forth in Table

5.

C. SUBFAMILY XENODONTINAE

The present study concerns the tribal allocations

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TABLE 4. CLASSIFICATION OF COLUBRID SNAKES (UNDERWOOD, 1967).

Infraorder Caenophidia

Family Dipsadidae

Subfamily Xenoderminae Pareinae Dipsadinae Calamarinae Sibynophinae Lycodontinae Xenodontinae

Family Homalopsidae

Subfamily Homalopsinae Boiginae Dasypeltinae

Family Natricidae

Family Colubridae

(NOTE: Underline indicates groups with xenodontine allocations.)

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE 5. CLASSIFICATION OF COLUBRID SNAKES (DOWLING

AND DUELLMAN, 1978)

FAMILY COLUBRIDAE

Subfamily XENODONTINAE (Neotropical Snakes) 93 genera, 577 species

Tribe Alsophiini 44 genera Dipsadini 25 Hydropsini 6 Nothopsini 9 Xenodontini 9

Subfamily LYCODONTINAE (Old World Swampsnakes) 79 genera, 285 species

Tribe Boaedontini 6 genera Lycophidini 10 Geodipsadini 9 Aparallactini 12 Pseudaspidini 6 Pseudoxyrhophini 9 Lycodontini 7 Xenodermini 4 Paretini 2 Oligodontini 4 Psammophini 7

Subfamily COLUBRINAE (Typical Harmless Snakes) 74 genera, 440 species

Colubrini 33 Lampropeltini 4 Sonorini 9 Philothamini 9 Boigini 11 Calamariini 8

Subfamily NATRICINAE (Watersnakes) 55 genera, 218 species

Tribe Natricini 34 genera Achrochordini 1 Homolopsini 10 Thamnophiini 9 Hydraethiopsini 4

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of the subfamily Xenodontinae. With 96 genera and 620+

species, the Xenodontinae is the largest subfamily of

snakes. Because these New World snakes lack distinctive

external characters which would readily differentiate them

from other colubrids, detailed analysis of the hemipenis

is essential for their proper identification.

D. HEMIPENES

Ophidian hemipenes are radically different from mam­

malian male intromittent organs. Hemipenes are cached

within the tail musculature, posterior to the cloaca,

rather than being external structures. At rest, the

tubular, paired structures are stored inside-out. Dur­

ing copulation one of the pair is everted, erected, and

extruded from the cloaca. It is turned inside out, like

the finger of a glove. Engorgment of vascular and lymph

sinuses provides the major force for erection and ever-

sion. Propulsor muscles assist the process (Murphy,

1980). After copulation, blood and lymph are drained

from the hemipenis and retractor muscles pull it back

into its original inside-out position within the tail

muscles. Retraction begins distally and proceeds to the

base of the organ. Figure 1 shows some distinctive fea­

tures of hemipenial morphology.

Because hemipenes show consistent patterns of shape,

ornamentation, and morphology at family, genus, and

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FIGURE 1. Features of Hemipeniai Morphology.

(HISS Drawing)

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Calyces

V 3 Spines

Sulcus spermaticu

Figure 1.

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species levels, they are among the most useful guides for

the snake taxonomist. Hemipenes may be single or bilobed.

Their shapes are described as subcylindrical, attenuate,

clavate, or bulbous.

The position of the sulcus spermaticus, the groove

in which sperm travel to the cloaca of the female, is

also of taxonomic significance. If the sulcus traverses

the hemipenis and ends on the lateral apical tip, it is

described as centrifugal. By contrast, if it ends on

the medial apex, the sulcus is centripetal. The sulcus

may be simple (unforked) or may fork at or near the

apical end of the hemipenis. The apex of the organ may

be capitate: separated from the rest of the lobe by a

ring of ornamentation, or it may be disked. Various

kinds and degrees of ornamentation may be present. Taxon-

omically significant ornamentation includes spines of

varying lengths and calcification, flounces, fringes, and

calyces (areas completely enclosed by borders of tissue)

(Dowling and Savage, 1960).

E .XENODONTINE HEMIPENES

The xenodontine hemipenis (Figure 2) was described

as different from other colubrid hemipenes in that it is

capitate or disked with a bifurcate sulcus. (The present

study has ascertained that this is not true for a number

of genera.) Although some have a single, capitate structure,

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FIGURE 2. Hemipenial, Maxillary, and Vertebral Character­

istics of Xenodontine Tribes

Species depicted are:

Alsophiini: Alsophis slevini

Dipsadini: Dipsas indica

Hydropsini: Hydrops marti

Nothopsini: Ninia diademata

Xenodontini: Xenodon severus

Note the diagnostic features of the hemipenes,

the diastema in the maxillary of Hydrops, and

the hypapophysis on the vertebra of Ninia.

(HISS Drawings)

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. without prohibited reproduction Further owner. copyright the of permission with Reproduced

DIPSADINI HYDROPSINI NOIHOPSINI XENODONTINI

lpure 15

most xenodontines have bilobed hemipenes. A typical xeno-

dontine hemipenis is ornamented with spines proximally

and calyces distally.

The Alsophiini and Hydropsini have semicapitate or

indistinctly capitate, bilobed hemipenes. The former

have ornamentation of spines and calyces, while the latter

have entirely spinose hemipenes. Dipsadini and Nothopsini

have fully capitate hemipenes. The Nothopsini are dis­

tinguished by the presence of hypapophyses on all body

vertebrae. The Xenodontini have disked hemipenes.

Table 6 details the hemipenial characteristics of Dow­

ling's five xenodontine tribes (Dowling and Duellman, 1978).

F. OTHER XENODONTINE CHARACTERISTICS

Hemipenial morphology alone is insufficient to define

the Xenodontinae. Other morphological characters must

be considered. The xenodontines generally exhibit a red­

uction in scale rows through the loss of the paraverteb­

ral rows. Often the upper jaw has a posterior diastema

(a space in the tooth row) followed by two enlarged, of­

ten grooved fangs. One group of xenodontines has verte­

brae with broad hypapophyses (single, median ventral pro­

cesses) (Dowling and Duellman, 1978), but none has hooked

hypapophyses characteristic of natricine snakes. Figure

2 shows hemipenis, maxillary, and vertebra of represent­

atives of Dowling's five xenodontine tribes.

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TABLE 6. SUBFAMILY XENODONTINAE (DOWLING AND DUELLMAN, 1978)

Tribe ALSOPHIINI (44 genera, 214 species)

Hemipenis bilobed (usually deeply) and semi-capitate (calyculate) with a bifurcate sulcus. No hypapophyses posteriorly.

Tribe DIPSADINI (25 genera, 215 species) Hemipenis slightly bilobed or single. Hemipenis distinctly capitate (calyculate). Sulcus usually forks in the capitate region, but is simple in some genera. No hypapop­ hyses posteriorly.

Tribe HYDROPSINI (6 genera, 22 species)

Hemipenis bilobed or single, spinose, and acalyculate. Hemipenis not capitate or disked, but with a bifurcate sulcus. No hypapophyses posteriorly.

Tribe NOTHOPSINI (9 genera, 21 species)

Hemipenis slightly bilobed, or single hemipenis which is distinctly capitate (caly­ culate) , and possesses a bifurcate sulcus. Broad, flat hypapophyses on the posterior body vertebrae.

Tribe XENODONTINI (9 genera, 74 species)

Hemipenis bilobed and spinose termina­ ting in a disk. No hypapophyses posteriorly.

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G. RATIONALE FOR THE PRESENT WORK

Although Dowling's colubrid taxonomic scheme is the

best devised thus far, it is not perfect. It has been

suggested, for example, that two of the tribes, the

Nothopsini and Hydropsini, are composite groups and

should not be recognized (Dowling and Duellman, 1978).

In addition, Dowling has transferred three genera, Gea-

gras, Pseustes, and Sympholis , to Subfamily Colubrinae

upon examination of their hemipenes (Dowling pers. comm.).

Subsequent to the publication of Dowling's classification

of the xenodontines, Elapomorphus, Tropidodryas, and

Crisantophis have been added to the subfamily ( Lema,

1970, 1979a, 1979b; Thomas and Dixon, 1977; and Villa,

1971). Finally, several of Dowling's genera have been

synonymized. Geatractus is in the synonomy of Tropido­

dipsas (Scott, 1967), Opisthoplus is in the synonomy of

Tomodon (Bailey, 1967), Paroxyrhopus is in the synonymy

of Xenopholis (fide Dowling), and Schmidtophis is in the

synonymy of Chersodromus (Scott, 1967).

Because of the enormous number of genera and species

involved, an intensive morphological investigation of

all xenodontine representatives to find those which are

erroneously grouped is a topic more fit for a life's

work, rather than a doctoral project. On the other hand,

a more restricted study, such as that of the two problem

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tribes, would not provide sufficient data for taxonomic

judgements. The true xenodontines would still not be

separable from those incorrectly included in the sub­

family. A literature search to define morphological

characteristics for each genus combined with zoogeographic

analysis of the ranges of the xenodontine tribes provides

a means for clarifying xenodontine systematics.

H. IMPORTANCE OF ZOOGEOGRAPHY TO SYSTEMATICS

It is often emphasized that good taxonomy is funda­

mental to good zoogeography. The two disciplines are

intimately related, but no simplistic cause and effect

relationship exists. Good taxonomy can just as well res­

ult from good zoogeographic analysis.

A memorable example of the way in which zoogeographic

analysis can affect taxonomy is the "New Guinea Snapping

Turtle." Its anomalous distribution (of Chelydridae)

included North America and New Guinea (Loveridge and

Shreeve, 1947). Even the most creative zoogeographers

were unable to suggest a plausible rationale. When the

type specimen was reexamined, under the prompting of

this disjunct distribution, the specimen was found to

be a damaged (road-killed), but otherwise normal, rep­

resentative of American Chelydra with erroneous data.

The taxonomic problem was solved because zoogeographic

considerations had questioned the validity of the initial

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premise. Devisia mythodes was placed into the synonomy

of Chelydra serpentina.

At this time a zoogeographic analysis of xenodontine

tribes appears appropriate because recent information

from plate tectonics, paleogeography, and refugium theory

has yet to be synthesized with ophidian taxonomy. An

understanding of these fields of information is crucial

to analysis of the distribution maps generated in this

work.

I. ZOOGEOGRAPHY OF XENODONTINE TRIBES

1. Factors Influencing Xenodontine Distributions

In the early 1970's Marguiles refocused the thinking

of cell biologists as she postulated that the key to the

evolution of the modern eukaryotic cell was to be found

within it. The separate genomes of chloroplasts and

mitochondria led her to the revelation that these organ­

elles were really cytoplasmic symbionts. In a similar

fashion, the key to the proper allocations of Subfamily

Xenodontinae is to be found by examining the history of

the New World as delineated by recent advances in paleo­

geography. The xenodontine distributions themselves

reflect this history, and if appropriately interpreted,

hold a record which reflects their evolutionary relation­

ships and thus their systematics.

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2. Physiography of Mexico and Central America

Topographical features of Mexico and Central America

are shown in Figure 3. Physiographic Mexico and Central

America are divided at approximately 20 degrees North

Latitude by a transverse belt of volcanic mountains, the

Neovolcanic Axis. To the north of this barrier stretch­

es the Mexican Plateau, with its two major subdivisions,

the Mesa Del Norte and the Mesa Central. The plateau

begins at the northern international border and gradually

rises from a height of 1000 meters in the north to 2000

meters above sea level at its southern edge. On the

west the plateau is bordered by the Sierra Madre Occiden­

tal; on the east by the Sierra Madre Oriental. Coastal

lowlands flank these two mountain ranges. The volcanic

Sierra Madre Occidental continues southward on the west­

ern coast as the Sierra Madre del Sur. As the Mexican

landmass narrows, a lowland feature, the Balsas Depression,

and the elevated Mesa del Sur meet the Isthmus of Tehuan­

tepec at the narrowest point of the Mexican landmass.

The Yucatan Peninsula, to the east, is a low limestone

platform. It communicates with the Chiapas-North Central

American Highlands, which are studded with the very high

peaks of the volcanic Sierra Madre de Chiapas.

South of the highlands of Central America is the

Nicaraguan Depression, a lowland area which separates

the Chiapas highlands from those found in Costa Rica

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FIGURE 3 Topography of Mexico and Central America

Redrawn from West, 1964

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»•©

Figure 3

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and Panama. These high mountains are bordered, especi­

ally on the Caribbean side, by lowland areas which ex­

tend into the South American continent, where they meet

the various cordilleras of the Andes. Figure 4 shows

the elevations of the Neotropical extension into Central

America (Savage, 1966; West, 1964).

3. Physiography of South America

Figure 5 shows the elevations at 0-600, 600-1500,

and above 1500 meters in South America. On the western

coast of the continent narrow strips of lowlands and

highlands meet the Cordillera Occidental of the Andes.

These strips continue south to south-central Chile. At

the southernmost portion of the continent, the Andes give

way to highland areas. These in turn, give way to low­

lands which extend to the tip of the continent. To the

west of the Andean Cordillera, another narrow strip of

highlands borders the extensive lowlands of the Amazonian

Basin. In the north the Amazon Basin is bordered by

the Venezuelan highlands. In the south-eastern portion

of Brazil the Amazonian Basin is bordered by highland

areas. In Paraguay and north-central Argentina, between

the Peruvian and southern Brazilian highlands is an

extensive swampy lowland that includes Paraguay and north-

central Argentina.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. N 3 U>

0-600 meters = lowlands 600+ meters = highlands Redrawn from Savage, 1965 FIGURE 4. Elevations of Middle America

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FIGURE 5• Elevations in South America

0-600 meters = c—’

600-1500 meters =

above 1500 meters = ••

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure 5

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 25

4. Plate Tectonics

These physiographic features have their roots in

the movements of the lithospheric plates which support

them. Figure 6 shows the plates involved. The North

American Plate extends to the south and abuts the Carib­

bean plate in the area of the Neovolcanic Axis. The

eastward movement of the Caribbean Plate, and the west­

ward movement of the North American Plate contribute to

the volcanic activity in this region. The Cocos Plate

abuts the Caribbean Plate on the Pacific coast of Mexico.

A subduction zone exists at the boundaries of these two

plates. The relative movements of these two plates, as

the Cocos Plate dives beneath the Caribbean Plate, create

the chain of volcanoes of the western coast of Mexico.

This chain continues down the coast of South America,

where the north-eastern movement of the Nazca Plate meets

the western-moving South American Plate (Dewey, 1972).

Geologists do not agree upon what causes these

plates to move. Major hypotheses are (1) movement of

convection currents in the earth's mantle, and (2) hot

spots which provide the impetus for continental drift.

Whatever the cause for their movement, the plates have

a long history of drifting, and are currently slowly

moving in different directions, and at different rates.

(For example, the North American plate is drifting west-

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FIGURE 6. Lithospheric Plates in the Western Hemisphere.

Redrawn from Dewey, 1972

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. > w jXf Wo(».T« ftncfciCAaf

V V * c W > ^ T V r a 3uto&c* 1 m l : fcU«**«A •* 'f\«««

• i\t* * €«r*»Vi|fcC "£•»*•*

Figure 6.

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ward at a rate of 2.5 centimeters per year ( a rate equiva­

lent to that at which human fingernails grow.)

5. Continental Drift; The Global History

Although the present work is primarily concerned with

the history of the western hemisphere, a thumbnail sketch

of the movements of all continental plates is necessary

to establish the correct historical perspective. The fol­

lowing synopsis is based on Dewey, 1972; Dietz and Holden,

1970; Freeland and Dietz., 1971; and Glen, 1975.

By Permian times (280-230 mybp) all of the contin­

ental plates had coalesced into one supercontinent, Pang­

aea. Surrounding Pangaea was a universal ocean, Pantha-

lassa. In Pangaea's northern hemisphere the Eurasian

plate abutted the North American plate. On its southern

margin the North American plate was congruent with the

African and South American plates. On its southeastern

margin the African plate was also joined to the Indian

plate, and farther south to the Antarctican plate. In

the southernmost portion of Pangaea the Australian plate

was united with Antarctica. In the Gulf of Mexico region,

four small plates, the microcontinents of Oaxaca, Nicara-

gua-Honduras, Yucatan, and South Eastern Bahama Platform,

formed a single landmass.

Although the exact time of the break-up is in question,

geologists believe that Pangaea began to fragment sometime

in the mid-Triassic (200 mybp). The first major split div-

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ded Pangaea into northern and southern supercontinents,

Laurasia and Gondwanaland. Laurasia was composed of the

merged North American and Eurasian plates, while Gond­

wanaland was composed of the South American, African,

Indian, Antarctican, and Australian plates. The initial

rift also created the Tethys Sea, a now-extinct seaway

between the independently drifting northern and southern

continental masses. At about the time that Pangaea div­

ided into Laurasia and Gondwanaland, the Indian plate

split from the southeastern border of the African plate.

It began a northward drift and would eventually collide

with the Eurasian plate to produce the Himalayan mountains.

At the end of the Jurassic (135 mybp) Africa and

South America began to diverge from south to north along

a mid-Atlantic spreading center between the two continent­

al plates. At this time the South Atlantic probably res­

embled the Red Sea in size. The North American and Eura­

sian plates were partially separated, but a land connection

existed via Greenland. The North Atlantic was only 600-

700 miles wide at this time, and because the North and

South American continents were not connected by a Central

American landbridge, the North Atlantic was openly connect­

ed with the Pacific Ocean.

By the end of Cretaceous time all modern continents

were recognizable, although Australia was still connected

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with Antarctica, and Greenland was still merged with north­

ern Europe. The differential movements of the South Amer­

ican and African plates had widened the South Atlantic to

nearly 1000 miles. Africa's northern drift had narrowed

the Tethys Sea. The independently moving North and South

American plates drifted westward rapidly. In its westward

movement, the western edge of the North American plate

overrode a north-south trench system. This collision prod­

uced the California Coast mountain ranges. Similarly,

South America ran into the Andes Trench. Instead of rid­

ing over it, however, South America pushed this trench

westward and altered the trench's orientation. The impact

initiated mountain building and diastrophism along the west

coast of the South American plate, and eventually produced

the Andes. In the early Cenozoic the mid-Atlantic rift opened

in the Arctic, separating Greenland from Europe. The Ind­

ian plate collided with the Eurasian plate, attaching the

Indian Peninsula to Asia, and producing the Himalayas.

North and South America were reconnected only in the late

Pliocene as orogeny and vulcanism elevated the Isthmus of

Panama.

6. Tectonics and Drift in the Western Hemisphere

Because of the four microcontinents (Oaxaca, Nicaragua-

Honduras, Yucatan, and the south-eastern Bahamas platform)

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that filled the Gulf of Mexico in the late Triassic (200

mybp), Middle America reached its maximum terrestrial area

at this time. On the north Middle America was connected

with North America; to the east, it was congruent with

the microcontinents; and to the west it abutted the north­

western portion of South America. At the end of the Tri­

assic (180 mybp) initial rifting associated with the frag­

mentation of Pangaea caused these once-contiguous micro­

continents to break up and begin to drift independently in

the newly-formed Tethys Sea. The Oaxaca landmass moved

northward to join the North American landmass. The Yucatan

and Honduras-Nicaraguan blocks rotated together at a point

near the Isthmus of Tehuantepec.

In early Jurassic time, the Gulf of Mexico continued

opening as Laurasia drifted southwestward. At this time

the Nicaraguan-Honduras/Yucatan landmass split apart. The

Gulf of Mexico, Caribbean Sea, and North Atlantic Ocean

were all small oceans at this time, divided by these drift­

ing microcontinents.

By the early Jurassic, the Yucatan and Nicaraguan-Hon­

duras landmasses arrived at their modern positions in rel­

ation to the North American continent. The Yucatan plate

submerged beneath the Caribbean Sea. North and South Amer­

ica were still not connected, although the Gulf of Mexico

was complete at this stage.

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In the late Jurassic (140 mybp) plate movements caused

a channel to form between northern Central America and

northwestern South America. Vulcanism produced a series

of ridges northwest of the Guiana Shield of South America,

an ancient landform which had been dry land since Pre-

cambrian times. A shallow seaway separated the Guiana

Shield from these ridges. Seaways intervened between the

Mexican Plateau and Costa Rica, between Costa Rica and Panama, and between Panama and South America.

In the lower Cretaceous (120 mybp) South America sep­

arated from Africa and began to drift westward in isolation.

North America was gradually separating from Eurasia. As

both North and South America moved westward independently,

both landmasses encountered subduction zones along their

western borders. The net effect of this and subsequent

plate collisions was to begin the Laramide Revolution, a

diastrophic event which initially produced the Pacific

Coastal Range, and eventually produced the Rocky Mountains

in North America, the Sierra Madre Occidental along the

western coast of Mexico, uplifted Nuclear Central Amer­

ica, and produced a second chain of volcanic archipelagos

to the northwest of that formed along the western coast

of South America in the late Jurassic. There is speculation

that the Laramide Revolution also raised a mass of dry land

from beneath the Caribbean Sea. Named Caribbean Land, this

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extinct landform was connected with Central America in the

Caribbean region and may have been the antecedent of the

Greater Antilles. Caribbean Land was separated from

North America by the Balsas Portal, a seaway the bisected

Mexico south of the present Neo-volcanic Belt. The Vene-

zuelan-Peruvian Geosyncline separated Caribbean Land from

South America. In North America an epicontinental sea

covered most of the central continental mass. It is hypo­

thesized that a volcanic archipelago (the Proto-Antilles)

joined North and South America in the late Cretaceous.

In the Paleocene (60 mybp) it is speculated that a

land bridge may have connected South and Middle America.

If this bridge existed, it was subsequently obliterated.

By the mid-Eocene (45 mybp) the Caribbean region had

attained its modern aspect. As North America drifted

faster than South America, the Caribbean region closed

slightly. Northern Venezuela and Panama were compressed

and distorted, because of the differential motion between

the North and South American plates. Vulcanism filled the

gaps between the two plates. The Colombian and Ecuadorian

Andes arose, and orogeny continued along the margins of

the South and Snorth American plates.

In the early Miocene (20 mybp) Caribbean Land founder­

ed and the Yucatan platform began to rise from beneath

the sea. It was dry land by the Pliocene. Costa Rica and

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Panama were volcanic archipelagos at this time, separated

by the Central American canals. Approximately 10-12 mybp

additional land emerged and coalesced with Nuclear Central

America. To the south the compression and uplift of the

Andes continued with extensive vulcanism until 4-5 mybp.

In the late Miocene (10 mybp) Middle and South America

came closer to being connected as Nuclear Central America

continued to be uplifted. The Isthmus of Panama, which

bridged the continental masses, was completed in the late

Pliocene. In the late Pliocene renewed volcanic activity

caused the Neo-volcanic range to be uplifted. As the Cocos

and Nazca plates beneath the Pacific Ocean were subducted

beneath the westward drifting North and South American

plates, vulcanism and uplift of the Cordilleran chain, the

backbone of the Andes, continued. The Peruvian orogenies

date from 20 mybp. The last Andean orogeny occurred in

Colombia 8.5 mybp.

7. Conclusions from Paleogeography

The following conclusions, drawn from the paleogeo­

graphy of the western hemisphere are pertinent to the pre­

sent work:

a. No direct connection existed between North and South

America from the Jurassic until the late Pliocene (+ 3 mybp).

b. During the Late Mesozoic South America had direct land

connection with Africa and with Australia via Antarctica.

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This connection lasted until the break-up of Gondwanaland

in the Eocene or Oligocene.

c. South America drifted westward in isolation from other

landmasses for 45 to 50 million years.

d. Central and South America were briefly connected by an

intercontinental landbridge during the Paleocene.

e. The Panamanian marine portal separated Nuclear Central

America from South America from the Eocene to the Pliocene.

f. Nuclear Central America and South America were connected

by the isthmus of Panama from the late Pliocene onwards.

g. The highlands of northern and lower Central America were

uplifted from the Miocene to the present.

8. Effects of Continental Drift on Biota

Movements of continental masses have the following

general effects upon their climates and thus their living

passengers:

a. As a landmass is pulled apart, its coastline increases.

Climates of continental coastlines are controlled and inf­

luenced by the size, location, and temperature of the oce­

ans which border them. In general, oceans mollify climates.

b. Interiors of large landmasses tend to be arid. Except­

ions to this general rule are those continents in which

orogenic rainfall reaches interior areas: for example the

precipitation in the Amazon basin.

c. Splitting of landmasses produces discontinuous or vi-

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cariant distributions. As each separated biota evolves

independently, it becomes increasingly different. In time

endemic species and higher categories will evolve. Endemic

organisms, therefore, are an indication of long-term

isolation.

d. Collisions of continental masses produce mountain ranges.

These affect wind patterns, precipitation, and temperature.

Collisions also reduce the available space for organisms.

The general effect of collisions of landmasses is increased

extinctions.

e. Connection of two landmasses, each with a unique biota,

leads to increased competition between similarly adapted,

previously isolated forms. Following Gause's rule, such

intermingling of biota results in eventual extinctions,

as well as increased rate of evolution.

9. Temperature and Precipitation

The curvature of the earth and the inclination of the

planet toward the sun determine the angle at which the

sun's rays strike the planetary surface. The most per­

pendicular rays strike the equator. The angle of incidence

becomes more and more oblique as one travels towards the

poles. At the poles the sun's rays are nearly parallel

with the surface. The basic distribution of temperature,

therefore, is latitudinal. Concurrently, temperature var­

ies seasonally because of the ecliptic path of the tilted

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earth around the sun and the precession of the earth's

axis.

If the earth's surface were uniform, there would be

uniform latitudinal bands of temperature girdling the

earth. Elevations of land reduce normal latitudinal val­

ues. Because soil and water absorb heat from insolation

differently (water being slower to heat and to cool than

soil), the general effect of large areas of ocean is to

reduce extremes of temperature at coastlines. This effect

produces an oceanic climate, which has moderate variations

in temperature, as well as less seasonality. Toward the

interior of large landmasses the climate is continental:

characterized by extremes of heat in summer and of cold

in winter.

The west-to-east rotation of the earth produces swirl­

ing air masses and descending centers of high pressure and

ascending centers of low air pressure. These affect land

temperature as well as precipitation. The rotation of

the earth also produces ocean currents of varying tempera­

tures which alter land temperature and affect precipita­

tion as well.

10. Climate

The concept of climate includes the prevailing weather

conditions of a region, as influenced by physiography of

landforms, temperatures of air and water currents, and

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FIGURE 7. Climatic Regions in the Western Hemisphere.

(Strahler, 1965)

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I i-j * tdMude climate*

H H I I Wet equatorial S B 10 Trade-wma uttorai tv. I |J Tropical desert and steppe E2 * West-coast desert ur 4 TfopiCdl iJwannd

II M jjie Jtitude chmate* Humid subt'opicai H Vjrme *est coast 7 Mediterranean £ □ < » Middle latitude Jesert and steppe t z i d % Humid contmentai

III H.Kh latitude climates . ! £ Continental subarctic f 1 3 Marine subarctic | | Tundra t- ~] 14 Icecap E H j Major highland areas

Figure 7.

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amount of insolation. Climate governs soil type and thus

the natural vegetation of an area. These factors interact

to produce habitable or hostile environments for cold

blooded vertebrates. Temperature and moisture are con­

sidered by Duellman (1968) to be most important in in­

fluencing the distributions of amphibians and reptiles.

When snakes disperse from an area, they will be successful

only in areas in which suitable temperature, moisture,

food, and shelter are found. Thus, for snakes the great­

est barriers to be overcome in range expansions, migrations,

or dispersals may be strange habitats, rather than physio­

graphic barriers (Udvardy, 1979). All of these factors

are controlled by climate.

11. Climatic Regimes

Figure 7 shows the climatic regimes in North, Middle,

and South America. The following discussion, which det­

ails the distribution and characteristics of these general­

ized climatic realms, is drawn from Leopold, 1961; Strahler,

1965; and Thompson and O'Brien, 1965.

Polar Climate or Tundra (1) is found north of 55° N

latitude in Canada's Northwest Territory, and south of 50°

S latitude, at the tip of South America in Tierra del

Fuego. Here polar air masses interact with northern Arctic

and southern Antarctic air masses to produce cyclonic

storms. The resultant climate is humid and very cold with

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no warm season or summer. The moderating influence of the

oceans is reflected in the phenomenon that the winters are

not as bitterly cold here as in the landlocked, interior

continental subarctic climate which adjoins the polar

climatic regime to the south.

The continental subarctic climate (2) is restricted

to North America and includes most of Canada and Alaska

between 50 and 70° N latitude. Here the winters are very

cold and summers are short and cool. Annual temperature

fluctuates over a wide range. Cyclonic storms, drawing on

maritime polar air, supply light precipitation. The cli­

mate is moist, however, because evaporation is slight.

Along the coast of Alaska and on Chilean islands off­

shore between 45 and 60° S the marine subarctic climate (3)

prevails. On these windward coasts and islands cool air

masses control the climate. Precipitation is relatively

high and the temperature range is small for such high lati­

tudes .

Along the Gulf of Alaska, down into Oregon and north­

ern California, between 40-60° N latitude, as well as along

the Chilean coast from 40-60° S latitude is the (4) marine

western coastal climate. This regime receives frequent

cyclonic storms with cool, moist maritime polar air masses.

As a result these coastal areas are cloudy, misty, and

rainy. The annual temperature range is small for middle

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latitudes.

In the eastern and north-central portion of the United

States, from 35-60° N latitude is the humid continental

climate (5). In this wide climatic regime, polar and trop­

ical air masses meet and clash. Seasonal contrasts are

strong, and precipitation is ample thoughout the year.

Middle latitude desert and steppe (6) adjoins the humid

continental climatic regime in the United States and bor­

ders the twin spurs of the Rocky Mountain Cordillera. A

southern extension, the tropical desert and steppe (13)

extends into Mexico. In Mexico the Sonoran and Chihuahuan

deserts are included in this regime. In South America the

middle latitude desert and steppe is represented by the

Patagonian desert in Argentina. Like the northern deserts,

the Patagonian is also bordered toward the equator by the

tropical desert and steppe. Small isolated patches of

tropical desert and steppe are located on the northern

margin of the Yucatan peninsula, and on Venezuela's north­

ern Caribbean coast. Continental-tropical air masses in

high pressure cells over the Tropics of Cancer and Capri­

corn produce arid to semi-arid climates with very high

maximum temperatures and moderate annual temperature range.

In contrast, the middle latitude desert and steppe regimes

are interior regions isolated from maritime air masses and

deprived of precipitation by mountains. These rain sha­

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. dow areas are dominated by continental tropical air masses

in summer and continental polar air masses in winter. The

annual temperature range is great, resulting in hot summers

and cold winters.

The California coast between 30 and 45° N latitude

and the Chilean coast between 30 and 45° S latitude have

a mediterranean climate. This regime is characterized by

a wet winter and dry summer (7).

The humid subtropical climate (8) extends over the

southeastern United States and southeastern South America

in Uruguay, the Argentinian province of Buenos Aires, and

the Brazilian province of Rio Grande do Sul. This regime

is produced by moist maritime airmasses flowing from the

western portions of oceanic high pressure cells. Here rain­

fall is abundant, and temperatures are warm. Winters are

cool with frequent cyclonic storms.

On both sides of the Mexican highlands, as well as in

the Isthmus of Tehuantepec, the Yucatan peninsula, northern

Colombia, in Venezuela, as well as in most of central and

southern Brazil, northeastern Bolivia, Paraguay, and north­

ern Argentina, the tropical savanna climate (9) holds sway.

This climatic regime has the widest distribution of any in

the Western Hemisphere. It has a marked alternation of

seasons: wet in summer, dry in winter. Summers tend to

be hot; droughts are common in winter.

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On the Caribbean side of Middle America east of the

Mexican highlands and on the east coast of the Brazilian

provinces of Espirito Santo and Bahia are trade wind lit­

toral climates (10). Here the easterly trade winds bring

maritime tropical air masses from moist western sides of

oceanic subtropical high pressure cells. These moist

winds produce narrow east coast zones of heavy rainfall

and uniformly high temperatures. Rainfall has strong sea­

sonal variation.

The Isthmus of Panama, Pacific coast of Colombia, and

Northern Ecuador, Amazonian Brazil, Guyana, Surinam, and

Cayenne have wet equatorial climates (11). This regime is

produced by warm, moist tropical and equatorial airmasses

which bring heavy daily rainfall through convection storms.

Temperatures are uniform thoughout the year.

The relatively cool, but extremely dry west coast des­

ert climate (12) occurs in the Baja Peninsula, and along

the Pacific coast of Ecuador, Peru, and northern Chile.

The foggiest and smallest desert in the world, the Atacama,

is included in this climatic regime. Cooled by cold ocean

currents, ocean winds which cannot hold or drop much pre­

cipitation blow across these deserts to produce condensation,

but little actual precipitation.

The symbol H in Figure 7 indicates highland areas.

As previously noted, altitude duplicates various climatic

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regimes. Thus a variety of climatic regimes are reproduced

vertically in highland areas. The climatic variation in

these highland areas is beyond the scope or need of the

present work.

In summary, the most important generalizations conc­

erning climate in the western hemisphere as they relate to

snake distributions include:

(a). The Caribbean coast of Middle America is moist and

humid with little temperature variation.

(b). The Pacific coast of Middle America is more xeric.

(c). Both of these climatic regimes continue into South

America in the crossover effect observed by D u n n (1931).

(d). In Middle America most of the landmass below 1500

meters is grouped as tropical. The Caribbean coast receives

two to three times as much rainfall as does the Pacific

lowlands and highlands.

(e). Middle and South America have very complex patterns

of climate which are reflected in a great diversity of

vegetational assemblages.

12. History of Climatic Change

In the Cretaceous both North and South America are

thought to have had subtropical climates. In succeeding

geological ages orogeny and new warm and cold ocean and

air currents produced the climatic mosaics observed today.

Although the manner in which this once widespread warm,

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moist climate was changed differ for the two continental

masses, the general pattern is the same: both areas be­

came progressively cooler and drier from high to low lat­

itudes. In South America the warm, wet tropical belt is

restricted to the Amazon Basin, the Isthmus of Panama, and

adjacent Pacific and Caribbean Colombia and Ecuador. In

North America the drying and cooling effect began in the

Rocky Mountains and spread to most of the Cordillera by

the mid-Tertiary. It had spread to the west coast, Great

Plains, and south to the Isthmus of Tehuantepec by the

Pleistocene (Rosen, 1978).

13. Vegetation

No attempts have been made to associate floristic and

herpetological patterns, probably because few herpetolog­

ists are knowledgable about the Middle American flora, and

few botanists are versed in the Middle American herpeto-

fauna. Furthermore, such an association seems to be poorly

founded. The distributions of reptiles and amphibians seems

to be most closely related to the physiognomic character of

vegetation, rather than to floristic association. This is

because terrestrial amphibians and reptiles, and especially

snakes, are groups of animals entirely independent of any

species of plants in feeding and breeding behavior (Duell-

man, 1966b).

Vegetation is the general effect produced by the growth

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of combinations of plant species (Good, 1964). The struct­

ural characteristics of vegetation are closely related to

climatic conditions. Thus, the same kind of vegetation

tends to occur in many parts of the world, although the

plant species involved (flora) may be different. For ex­

ample, the desert vegetation of the Sonoran and Atacaman

deserts appear to be very similar, although the plant

species may differ.

Duellman (1966b), Savage (1966), and Stuart (1966) have

made important contributions to the understanding of the

manner in which the distributions of cold blooded verte­

brates are related to vegetation. Duellman's approach is

the most cogent. He considers precipitation and tempera­

ture as the most critical factors governing the distribution

of cold blooded vertebrates. Using fifteen hundred meters

of elevation as the dividing line between lowland and high­

land areas, Duellman recognizes four zones of lowland

vegetation.

a. The evergreen rainforest zone is widespread on the Cari­

bbean lowlands of Central America. Yearly temperature has

only moderate seasonal fluctuations in this zone. In most

places definite dry and rainy seasons exist, although the

climate is moderately moist all year. A continuous treetop

canopy allows shade and moisture-loving amphibians and rep­

tiles to abound. The arboreal microhabitat is well developed

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and is extensively used by the herpetofauna.

b. Broad-leafed forest occurs on the Caribbean lowlands

of Central America, as well as on parts of the Pacific

lowlands. It is less humid than the evergreen rain­

forest, and has a marked dry season. Sunlight is more

intensive, drought is more severe, and temperatures are

higher than in the evergreen rainforest. These drier

conditions exclude some amphibians and reptiles.

c. Scrub forest is widespread and nearly continuous on

the Pacific lowlands from the Isthmus of Tehuantepec to

the Peninsula de Nicoya of Costa Rica. This vegetation

zone has a prolonged dry season and high temperatures.

Both these conditions have a desiccating effect on all

life forms. Amphibians and reptiles that are adapted to

subhumid conditions occur here.

d. Savanna is scattered through the Caribbean lowlands of

southern Mexico to eastern central Nicaragua. Duellman

considers savannas to be relict habitats with relict pop­

ulations of amphibians and reptiles. The herpetofauna

includes members of the ecological assemblage found in

the scrub forest. Some species even extend their ranges

to the adjacent broad-leafed forests.

Duellman's second major vegetational grouping in Cen­

tral America is above the 1500 meter level. In Central

America the land above 1500 meters is characterized by

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warm temperate conditions. The temperature is warm to

moderately cool. Frosts occur occasionally at higher

elevations. The mean annual temperature does not exceed

18°C. Duellman recognizes three kinds of highland vege­

tation :

a. Cloud forest is found on windward slopes, especially on

Caribbean sides of mountains. Clouds cover these slopes

daily throughout the year. The vegetative formation is

distinctive, providing an unusual habitat: cool and very

wet. The cloud forest is discontinuous. It is most ex­

tensive on the northern slopes of the Chiapan-Guatemalan

highlands, in the highlands of Central Honduras, and in

the Cordillera Talamanca in Costa Rica and Panama. This

is an optimal habitat for many species of amphibians and

reptiles, but especially for frogs.

b. The oak-pine forest is a mixed stand of pines and oaks

found on elevations between 1000-2000 meters in the high­

lands of northern Nicaragua and northwestern Central Amer­

ica. The climate is subhumid and the herpetofauna is

distinct from that of the highlands of lower Central Amer­

ica (Costa Rica and Panama).

c. Alpine and subalpine habitats are found at elevations

above 2600-2800 meters. These cool, moist habitats are

found in the highlands of Chiapas, Sierra de los Cuchumat-

anes in Guatemala, and in the southwestern highlands of

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Guatemala. The alpine and subalpine habitats have deep

growths of mosses, and shelter for small secretive species

is plentiful.

In his analysis of the Central American herpetofauna

Duellman uses these vegetation zones as bases for his Cen­

tral American Herpetofaunal Assemblages, delimited by

moisture and elevation.

The Humid Tropical Assemblage ( Figure 8 ) encompasses

the evergreen rainforest and broadleafed forest. On the

Caribbean lowlands this assemblage stretches southeast­

ward across the base of the Yucatan Peninsula to South

America. In South America it continues southward on the

Pacific lowlands of Colombia to northern Ecuador. Dis­

junct portions are found on the Pacific lowlands of east­

ern Chiapas and southwestern Guatemala and in the Golfo

Dulce region of Costa Rica. The Humid Tropical Herpeto­

faunal Assemblage has a high percentage of arboreal snakes

in comparison with other assemblages. Imantodes cenchoa,

Leptodeira septentrionalis, L. ornata and Leptophis ahae-

tulla plus various species of Dipsas and Sibon are arb­

oreal xenodontines that inhabit this region. Pliocercus,

Rhadinaea, and Tantilla inhabit the forest floor. Clelia

clelia, Coniophanes fissidens, and Xenodon rhabdocephalus

are members of the assemblage, but are neither arboreal

nor burrowing.

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FIGURE 8 Humid Tropical Assemblage in Central and

South America

Redrawn from Duellman, 1966b.

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. o

III

>v Figure Figure 8 (Cont'

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FIGURE 9: Arid Tropical Herpetofaunal Assemblage in

Central America and Northern South America

Redrawn from Duellman, 1966b.

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FIGURE 10: Humid Montane Herpetofaunal Assemblage in

Central America and Northern South America

Redrawn from Duellman, 1966b.

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The Arid Tropical Herpetofaunal Assemblage inhabits

subhumid scrub forest and savanna habitats (Figure 9).

The Arid Tropical Assemblage is found on the Pacific

lowlands from Sinaloa to the lowlands of Panama. On the

Caribbean coast it extends from Tamaulipas and the Rio

Grande Embayment of Texas to Veracruz. Disjunct areas

of the Arid Tropical Assemblage occur in the northern

Yucatan peninsula, and interior valleys of northern

Central America. In the south the assemblage is found on

the Caribbean lowlands of Colombia and Venezuela. Lepto-

deira annulata, L. nigrofasciata, and Trimorphodon, all

nocturnal snakes, are found in this assemblage.

The Humid Montane Assemblage (Figure 10) includes

cloud forest and low montane wet forest which is discon-

tinuously distributed between 1000 and 2000 meters on

windward mountain slopes. The Humid Montane Assemblage

occurs in Eastern Mexico as far north as Tamaulipas and

on Pacific slopes in Guerrero and Oaxaca. A major dis­

continuity exists at the Isthmus of Tehuantepec. In

northern Central America the humid montane area is cont­

inuous on Pacific slopes from northern Chiapas to northern

Nicaragua. It is found farther south on both Pacific and

Caribbean coasts of mountains in Costa Rica and western

Panama. To the south it is found in the northern Andes.

Geophis, Rhadinaea, Ninia, Amastridium, Adelphicos, Plio-

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cercus, Trimetopon, and Tropidodipsas are xenodontine mem­

bers of the Humid Montane Herpetofaunal Assemblage.

The Arid Montane Assemblage (Figure 11) encompasses

the pine-oak forests of southern Mexico and northern Cen­

tral America. A discontinuity exists at the Isthmus of

Tehuantepec. Farther south the assemblage is distributed

through the highlands of Chiapas, Guatemala, and Honduras

to northern Nicaragua. Eleven species of snakes (not

specified by Duellman) inhabit the arid montane area.

The High Montane Herpetofaunal Assemblage occurs at

elevations over 2500 meters, encompassing the alpine and

subalpine habitats of fir or cypress forests, montane

meadows, cool broad-leafed forests, and paramo. Tempera­

tures sometimes fall below freezing in these highlands.

The most extensive, but discontinuous highlands are in

Mexico. This disjunct pattern continues in southern Chia­

pas, Guatemala, and Western Honduras, as well as on the

highest mountains in Costa Rica and Western Panama. As

might be expected, the High Montane areas are not optimal

snake habitat. There are only two species of snakes in

Central America and four species in the Mexican highlands

which belong to this herpetofaunal assemblage.

14. Biotic Provinces

Biotic provinces are the result of attempts to corre­

late ecological and distributional information. These

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FIGURE 11: Arid Montane Herpetofaunal Assemblage in

Central America

Redrawn from Duellman, 1966b.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure Figure 11.

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FIGURE 12: High Montane Herpetofaunal Assemblage in

Central America

Redrawn from Duellman, 1966b.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure Figure 12.

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FIGURE 13: Biotic Provinces of Mexico.

Redrawn from Goldman and Moore, 1946

1 = California

2 = Guadelupe Island

3 = Vizcaino Desert

4 = Southern Baja California

5 = Revilla Gigedo

6 = Sonora

7 = Sierra Madre Occidental

8 = Chichuhua-Zacatecas

9 = Tamaulipas

10 = Sinaloa

11 = Nayarit-Guerrero

12 = Sierra Madre Oriental

13 = Transverse Volcanic

14 = Veracruz

15 = Sierra Madre del Sur

16 = Tehuantepec

17 = Chiapas Highlands

18 = Yucatan Peninsula

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure 13.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 57

geographic areas are thought to be distinctive because of

peculiar vegetation type, ecological climax, endemic flora,

and endemic fauna (Axtell, 1962). Goldman (1946) used

mammalian distributions to define the biotic provinces of

Mexico (Figure 13). Stuart (1943) used the distributions

of salamanders to erect biotic provinces in Guatemala.

Smith (1949) used the distribution of lizards to map the

biotic provinces of Mexico and Guatemala (1949). Hershko-

vitz (1958) subdivided the Neotropical Region based on

mammalian distributions. Ryan (1963) mapped the biotic

provinces in Central America on the basis of mammalian

distributions. Halfter (1964) used biotic provinces to

explain the distribution of the Mexican entmofauna.

A serious limitation of biotic provinces for the cur­

rent study is that they require far more detailed ecol­

ogical knowledge than is presently available for the

xenodontine snakes. One is forced to agree with Duellman's

conclusion that, on the basis of present knowledge, the

recognition and delimitation of biotic provinces, espec­

ially with regard to the xenodontine snakes, is "an

exercise in zoogeographic frivolity" (Duellman, 1966).

15. Importance of the Genus to Zoogeographic Analysis

In analyzing the ranges of the xenodontine snakes

a conscious decision was made to emphasize the ranges of

genera, rather than the ranges of species, or other taxo-

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nomic level. The species is too small a unit to be useful

in the consideration of large scale problems. Not only

are the family, subfamily, and tribe categories which are

too large to handle, but also analysis of these taxonomic

levels would not aid in a determination of the correct

tribal allocations of the xenodontine snakes.

The genus is considered by most authors (Good, 1964)

to be the most important and illuminating of all categor­

ies used in zoogeographic analysis. Genera are usually

of convenient size, and composed of members which possess

the same value. In addition, each genus is a monophyletic

group (Good, 1964).

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MATERIALS AND METHODS

A. MAP CONSTRUCTION

In the first phase of this project a data base was

established from which distribution maps for each xenodont­

ine specices were to be computer drawn. The following

sources provided locality data for genera and species in

the geographic areas with which the study was concerned:

North America:

Conant, 1975; Fitch, 1949; Logier and Toner, 1961;

Stebbins, 1966; Tanner and Banta, 1966; Van Denburgh,

1895; Wright and Wright, 1957.

Mexico:

Alvarez, 1960; Bogert and Oliver, 1945; Dixon, Ket-

chersid, and Lieb, 1972; Duellman, 1958b, 1960, 1961,

1965; Dunn, 1931; Hardy and McDiarmid, 1969; Leviton

and Banta, 1964; Martin, 1958; McCoy and Van Horn, 1962;

Smith, 1943; Smith and Brandon, 1968; Smith and Lan-

gebartel, 1949; Smith, Lynch, and Altig, 1965; Smith

and Taylor, 1945, 1950, 1966; Smith and Williams,

1963; Wilson and McCranie, 1979.

West Indies:

Dunn, 1933; Dunn and Saxe, 1950; Long, 1974; Maclean,

Kellner, and Dennis, 1977; Maglio, 1970; Schwartz and

Thomas, 1975; Schwartz, Thomas, and Ober, 1978; Ste-

jneger, 1917.

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Central America:

Dueliman, 1963; Dunn, 1931, 1933, 1937, 1942; Hender­

son and Hoevers, 1975; McCoy, 1966; Mertens, 1952;

Myers, 1969, 1972; Myers and Rand, 1969; Neill and

Allen, 1959; Peters and Orejas-Miranda, 1970; Savage,

1973; Stuart, 1948, 1950, 1963; Taylor, 1951, 1954,

1955.

South America:

Abalos and Mischis, 1975; Amaral, 1930a, 1930b, 1930c,

1935, 1976; Cope, 1868; Dixon and Soini, 1977; Dunn,

1957; Lema and Fabian-Beurmann, 1977; Peters, 1958,

1960; Peters and Orejas-Miranda, 1970; Roze, 1966;

Santos, 1955.

Locality data also were collected from monographs and

papers concerned with xenodontine snakes. These are list­

ed as references on each generic summary in the data sec­

tion which follows.

Latitude and longitude coordinates for each locality

were found by consulting atlases, maps, and gazeteers.

The following sources were used:

Defense Mapping Agency Topographic Centers: Gazeteers

for Surinam and French Guiana; Guyana and Nicaragua.

Division of Geography, Department of the Interior: Gaz­

eteers for Bolivia and Costa Rica.

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Geographic Names Division, Army Topographic Command Gaz­

eteers for Panama and Canal Zone.

National Geographic Society Map Supplement of Mexico,

Central America, and the West Indies.

Office of Geography, Department of the Interior: Gaz­

eteers for Uruguay, Peru, Mexico, Honduras, Paraguay,

Ecuador, Guatemala, Guyana, Panama, French Guiana,

Bolivia, Argentina, Cuba, and Venezuela.

Rand McNally International Atlas.

The locality coordinates for each species were record­

ed and stored in the computer facilities at City Univer­

sity New York Computer Center.

Using a modification of the DISPLA computer program

(Display Integrated Software System and Plotting Language),

a graphics software package available through Integrated

Software Systems Corporation, San Diego, California, the

locality coordinates for each species were plotted on com­

puter-drawn outline maps of the pertinent geographic areas.

The maps use a Mollweide projection which minimizes dis­

tortion in temperate regions. The scale of the computer-

drawn maps varies with the extent of the geographic range

depicted.

B. MAP ANALYSIS

The spot maps for each species were compared with the

locality data, and then the range of each species was hand

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drawn onto each map. Considerations in outlining ranges

included the highland and lowland areas shown in Figures

4 and 5 as well as vegetation zones shown in Figure 7, and

in the case of Middle America, the Herpetofaunal Assem­

blages shown in Figures 8 to 12. Often the locality data

indicated a wide portion of a continent, or an entire state.

In the absence of ecological information, the entire nat­

ional boundary was used. When elevation or habitat pref­

erence data were available, these helped to delimit the

range of a species.

The generic maps were assembled by superimposing the

specific maps. In cases such as Atractus, Geophis, Dipsas,

or Rhadinaea, which have been subgenerically grouped, maps

of these groups were made. Most genera had too many species

to conveniently show all species on one map. Thus, mult­

iple generic maps were made.

C. MORPHOLOGICAL INFORMATION AND ERECTION OF NEW TRIBES

An extensive literature search was the information

base for generic summaries. These summaries, included in

the Data section which follows, give all available infor­

mation concerning the morphology, head scutes, scutellation,

hemipenis, vertebrae, geographic range, habits, generic rel­

ationships , and references for each genus. When no infor­

mation was available this is indicated.

An attempt was made to examine the hemipenis of each

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xenodontine genus. The following specimens were examined

at the United States National Museum:

Adelphicos quadrivirgatus: USNM 46612 Chiapas

Chersodromus: USNM 7102 Orizaba

Contia tenuis mitis: USNM 204812, USNM 204813

Crisantophis nevermani: USNM 194379 Nicaragua

Diadophis punctatus HGD 75018 North Carolina

Eridiphas slevini: CAS 134804 Baja Sur

Geophis nasalis: USNM 127964 Guatemala

Helicops angulatus: USNM 204140 Ecuador

Ninia atrata: USNM 166721 Trinidad

N. sebae: USNM 109828 Veracruz

Pseudablabes agassizi: USNM 72398

Pseudoeryx plicatilis: USNM 5802 Paraguay

Pseudotomodon trigonatus: USNM 734552 Argentina

Rhachidelus brazili: USNM 100753 Rubriao Junior, S. Paulo

Scolecophis atrocinctus: USNM 72396 Costa Rica

Simophis rhinostoma: USNM 39072 Lencois Paulista, S. Paulo

Sordellina punctata: USNM 200693 Camburiu Guimaraes, S. Paulo

Tachymenis

Tantillita lintoni: USNM 71787 Peten, Guatemala

Thamnodynastes strigatus: USNM 71194

Tomodon dorsatum: USNM 56343 Brazil

T. ocellatus: USNM 9815 Brazil

Trimetopon pliolepis: USNM 75036

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Umbrivaga UTAMM R3971

Drawings of hemipenes of xenodontines made by Herpeto-

logical Information Search Systems and unpublished were

used for comparisons of xenodontine hemipenes. HISS draw­

ings of the following genera were used in hemipenial

analysis:

Alsophis slevini AMNH 91474

Apolstolepis flavotorquata UMMZ 108808

Arrhyton callilaemus ASFA V12553

A. exiguus ASFS X7533

A. taeniatus AMNH 46684

A. vittatum ASFS V6233

Coniophanes fissidens UMMX 87640; HGD 110

C. imperialis HGD 113

C. lateralis

C. picevittatus

Conophis vittatus HGD 662

Crisantophis nevermanni AMNH 104032

Darlingtonia haetiana haetiana ASFS 2078

Diadophis punctatus HGD 204

Dipsas indica HGD 890

Drepanoides anomalus HGD 689

Enulius unicolor AMNH 71358

Erythrolamprus aesculapii HGD 102

Farancia abacura HGD 681

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F. erytrogramma HGD 122

Helicops angulatus HGD 713

H. leopardinus HGD 83

H. pictiventris HGD 84

Heterodon platyrhinos HGD 512

Hydrodynastes bicincta AMNH 60822

H. gigas HGD 565

Hydrops marti HGD 572

Hypsiglena torquata orchorhynchus HGD 718

Hyp s irhynchus ferox HGD 710

Ialtris dorsalis HGD 891

Leimadophis almadensis HGD 722

Leptodeira annulatus HGD 864

Liophis cobella HGD 721

Lygophis lineatus HGD 76

Lystrophis d'orbignyi AMNH 91519

Manolepis putnami HGD 737

Ninia diademata HGD 743

Oxyrhopus petola HGD 742

Philodryas olfersi HGD 754, AMNH 87956, UMMZ 108988

Phimophis guianensis HGD 752

Pliocercus elapoides HGD 778

Pseudoboa coronata HGD 781

Pseudoeryx plicatilis HGD 566

Ptychophis flavivirgatus HGD 783

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Sibon nebulatus HGD 768

Sibynomorphus mikani HGD 764

Siphlophis cervinus

Tachymenis peruviana HGD 790

Tantalophis discolor

Tomodon dorsatum HGD 838

Tretanorhinus variabilis HGD 831

Trimorphodon latifascia HGD 562

Tripanurgos compressus HGD 852

Tropidodipsas fasciata HGD 857

Uromacer catesbyi HGD 846

Uromacerina ricardinii HGD 848

Xenodon severus HGD 545

Xenopholis scalaris HGD 345

After analysis of the morphological data for xenodontine

genera, it was evident that the bases upon which some of

Dowling's tribes (1978) had been erected were erroneous.

Possession of hypapophyses on posterior vertebrae, the

character used by Dowling to define the Tribe Nothopsini,

was rejected as a tribal character because the status of

the significance of hypapophyses as taxonomic characters

amongst the xenodontines has yet to be fully evaluated.

Since some colubrid genera have species which have and

others which lack posterior hypapophyses (Chrysopelea,

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for example) the taxonomic importance of posterior hypa­

pophyses is in question.

The xenodontine genera for which there was hemipenial

information followed seven patterns. The majority of

genera had a forked sulcus. Amongst these the hemipenis

w a s :

a. noncapitate, entirely spinose with no calyces, or

b. semicapitate, with spines and calyces, or

c. bicapitate with spines and calyces, or

d. disked with spines and no calyces, or

e. fully capitate with spines and calyces.

Those genera with a simple sulcus had fully capitate hemi­

penes with spines and calyces. Genera with a simple sul­

cus and no capitation were allocated to Subfamily Colubrinae.

Seven xenodontine tribes were erected to accommodate

each of these distinctive kinds of hemipenes. After the

tribal allocations had been made, other morphological sim­

ilarities were sought within each tribe.

The ranges of the seven xenodontine tribes were plot­

ted by superimposing and redrawing generic maps onto a

base map. Distinctive patterns were found for each tribe.

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D. EXPLANATION OF GENERIC SUMMARIES

The following alphabetically arranged generic sum­

maries incorporate details of morphology, habit, and

taxonomy, as well as give pertinent literature citations

and distributional maps. The morphological information

served as a base for the erection of new xenodontine

tribes. Distribution maps for each tribe were used as

a test of the validity of the tribes. Both sources of

information are contained in the following generic sum­

maries. These data are organized in the following

manner:

1. The heading for each genus includes the name

and original describer of the genus, and the type species,

as well as the number of species in the genus.

2. Under MORPHOLOGY are included the details of

external morphology: body shape, length of tail, max­

imum body and tail lengths, whether the head is distinct

from the neck; and size and shape of the eye.

3..The first paragraph of SCUTELLATION details any

deviations from the normal colubrid pattern of head

scutes. This normal pattern is defined as including:

a rounded rostral, 2 intemasals, 2 prefrontals, 2 sup-

raoculars, 1 frontal, 2 parietals, 2 nasals, 1 loreal,

1 or 2 preoculars, 2 or 3 postoculars, 1+2 to 2+3 tem­

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porals, 7 or 8 supralabials, 9-11 infralabials.

The second paragraph under SCUTELLATION gives det­

ails of body scutellation. Number of dorsal scale rows,

condition of dorsal scutes (smooth, keeled, striated),

number of apical pits, special features of dorsal scales

(i.e., vertebral row enlarged), number and condition of

ventral scutes (rounded or angulate), condition of anal

plate (single or divided), number and condition of cau­

dal scutes (single or divided).

4. The maxillary formula appears as the first num­

bers in the DENTITION information. A + indicates the

presence of a maxillary diastema. Arabic numerals fol­

lowing the + indicate postdiastemal teeth; Roman num­

erals following the + indicate postdiastemal fangs (i.e.,

grooved teeth). The remaining dental information relates

to size of maxillary teeth, and number of mandibular,

palatine, and pterygoid teeth, where available.

5. The information under VERTEBRAE relates to the

presence of hypapophyses on posterior body vertebrae,

presence of enlarged neural spine, and presence of enl­

arged or flattened zygapophyses.

6 . The HEMIPENIS portion of the generic summary

gives the description of this organ. All descriptive

te rms, except bicapitate are as recognized by Dowling

and Savage, 1960. The following terms are used:

a. condition of sulcus spermaticus: forked or

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simple (unforked).

b. shape: single, bilobed, slightly bilobed.

c. capitation: noncapitate, semicapitate, bicap-

itate, capitate, disked. A noncapitate hemipenis may

have apical calyces or be acalvculate. A bicapitate

hemipenis has calyces restricted to the apices of a

bilobed organ.

d. ornamentation includes spines, spinules, floun­

ces, calyces, and papillae.

7. The GEOGRAPHIC RANGE of the genus is detailed

in the next section of the generic summary.

8 . Available ecological information is included

under HABIT.

9. The opinions of other authors as to GENERIC

RELATIONSHIPS are summarized in the next paragraph of

the generic summary. The names in parentheses refer

to the specific literature citations which follow in

the REFERENCES section.

10. Figure LEGENDS for the distributional maps fol­

low in the final portion of the generic summary.

11. The range of each genus is indicated (often

highlighted by an arrow) at the bottom of each generic

summary.

12. Distributional maps of species within each

genus follow the generic summary. If subgeneric groups

have been erected, species are grouped accordingly.

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GENUS: Adelphicos Jan, 1862 TYPE SPECIES: Adelphicos quadrlvlrgatus Jan CONTENT: 2 species (see LEGEND)

MORPHOLOGY: Cylindrical body, short ta il; maximum total length: 400 mm. Head small, conical, not distinct from neck. Eye: small with round p u p il. SCUTELLATION: Head scutes modified: rostral very small; 0 preocular; loreal elon­ gate; temporals 1+1,posterior longer than broad; anterior chin shields enlarged, in contact with lip or not.

15 dorsal scale rows; dorsals smooth with 0 apical pits. 121-148 ventral scutes, ventrals rounded; anal divided; 22-49 caudal scutes, caudals divided. DENTITION: 9-10 m axillary teeth which decrease in size posteriorly, largest teeth near middle of maxilla; 9-12 mandibular teeth, greatly red­ uced in size posteriorly. VERTEBRAE: Hypapophyses not present posteriorly, neural spine not enlarged; zygapophyses not enlarged. HEMIPENIS: Hemipenis is single or only very slightly bilobed. It has a simple sulcus, is fully capitate, and spinose (Smith). Smith's original description also recorded flounces. This finding has not been sub­ stantiated. The reported simple sulcus needs corroboration. Pap­ illae and tiny calyces ornament the apex (Dowling). GEOGRAPHIC RANGE: Adelphicos is a Middle American genus, found in southern Mexico and northern Central America. I t is found on A tlantic slopes from cen­ tr a l Veracruz to central Honduras, and on P acific slopes from cen­ tral Guatemala to central Oaxaca. It also inhabits interior valleys of Guatemala and Chiapas. I t is not found on the Yucatan peninsula. HABIT: Inhabits cloud forests: 1500 m. Adelphicos is in Duellman's Humid Montane Assemblage. A. verapacis is an upland form. Oviparous. GENERIC RELATIONSHIPS: In a ll respects but hemipenis, Adelphicos resembles Geophis. Its simple sulcus and absence of calyces make it an isolated form (Smith). Adelphicos is derived from Geophis, which is derived from Atractus. Adelphicos shows coalescence of bifurcate elements and head scutes, and coalescence, loss, or reduction of size of various scutes. A. verapacis is the most primitive member (Stuart). REFERENCES: Boulenger, 1894; Cope, 1895; Duellman, 1966; Savage, 1966; Smith, 1942c; Stuart, 1950. LEGEND FOR FIGURE 14: Geographic D istribution of Adelphicos verapacis Hquadrlvlrgatus

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 85° TF 95° W

Figure 14.

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GENUS: Alsophis Fitzinger 1843

TYPE SPECIES: Psammophis an tillen sis Schlegel

CONTENT: 16 species (see LEGEND)

MORPHOLOGY: Body cylindrical, ta il long; maximum total length: 1950 mm, maxi­ mum t a i l length: 550 mm; head slig h tly d istin ct from neck; eye large or medium; pupil round. SCUTELLATION: Head scutes normal except that loreal is missing in A. a te r.

17-23 dorsal scale rows; scales smooth, 0-2 apical pits; 160-230 ventral scutes; ventrals rounded, or angulate. Anal divided (may be single in A. santicrucis) . 100-162 caudal scutes; caudals divided. DENTITION: 12- 21+2 maxillary teeth, post-diastemal teeth strongly enlarged, but ungrooved and separated by a conspicuous diastema. 17-35 mandibular teeth, anterior much longer than posterior. 9-16 palatine teeth. 20-32 pterygoid teeth. VERTEBRAE: Hypapophyses not present posteriorly. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, semicapitate with a forked sulcus. Sulcus div­ ides near the base of the organ. Each branch extends to the tip of one lobe of the deeply bifurcated apex. Several rows of longitudi­ nally arranged, stout spines are present along the middle half of the organ. These grade into numerous smaller spines basally. Base may be nude or have long plicae. Sulcus is bordered by a fringe of folded tissue bearing modest-sized, closely spaced spines that grade into smaller ones distally. On the apex of each lobe a reticulated network of tissue surrounds the sulcus with moderate to long, f i l i ­ form, papillate calyces. GEOGRAPHIC RANGE: Greater and Lesser Antilles, Peru, Chile', Argentina, and Galapagos Islands. HABIT: Semiarboreal. A. cantherigerus feeds on bats. GENERIC RELATIONSHIPS: Alsophis is d ifferen tiated into mainland and island forms (based on number of apical pits). Philodryas, Conophis occupy the geographic areas which the ancestral genus must have inhabited, i f the West Indian representatives of this group were derived by waif dispersal from the mainland. The rear fangs of the la tte r genera preclude them from direct ancestry to the non-fanged A ntillean group. REFERENCES: Hardy, 1957; Maglio, 1970; N e ill, 1954; Schwarl and Thomas 1960.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. LEGEND FOR FIGURE 15: Distribution of Species of Alsophis

v>anomalus M»ater A antillensis // cantherigus — melanuchus ^ portoricensis • rijersmai {'/ rufiventris © santicrucris ^ vudii

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22 N iue 15. Figure \ 66 73

FIGURE 16: D istribuiton of Species of Alsophis

• dorsalis

// biserialis

o slevin i

FIGURE 17: D istribution of Species of Alsophis

• angustilineatus

/ j chamissonis

rr^. tachymenoides

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 85° W Figure 16.

Figure 17.

75 W 65 W LONG

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GENUS: Amastridium Cope, 1860

TYPE SPECIES: Amastridium veliferum Cope

CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body elongate, cylindrical, with a slender, medium-length ta il. Maximum total length: 724 mm. Body to ta il ratio: 0.24 - 0.319. Head d is tin c t from neck. Eye medium-sized with a round pupil. SCUTELLATION: Head scutes normal except that lo real is variable: present or not.

17 dorsal scale rows, scales smooth, keeled scales in posterior rows; apical pits in neck region only. 119-170 ventral scutes. Anal div­ ided. 68-86 caudal scutes, caudals divided. DENTITION: 11-17+11 m axillary teeth. Prediastemal teeth subequal in size. En­ larged rear teeth grooved or not. VERTEBRAE: Hypapophyses present on posterior vertebrae. Neural spine not enlarg­ ed. Zygaopohyses not enlarged. HEMIPENIS: Hemipenis is single, noncapitate with a forked sulcus, spines, and calyces. Hemipenis is s lig h tly clavate. Sulcus forks at junction of spinose and calyculate area; basal 2/3 is spinose; distal 1/3 is calyculate; 2 enlarged spines at base. GEOGRAPHIC RANGE: Nuevo Leon, Mexico to Panama. A tlan tic and P acific versants from Nuevo Leon south. In Mexican states of Nuevo Leon, Tamaulipas, Vera­ cruz, Chiapas, and Oaxaca. HABITS: T e rre s tria l, secretive; found in wet A tlan tic lowlands and uplands in Costa Rica 100-1500 m. GENERIC RELATIONSHIPS: Amastridium does not appear to be closely related to any other Mid­ dle American snakes. Savage included Amastridium in the Middle Amer­ ican Historical element. Scott indicated that Amastridium is not closely related to any other Middle American group. Smith recogn­ izes 2 species (A. veliferum and A. sapperi) . REFERENCES: Boulenger, 1894; Savage, 1966; Scott, 1969; Smith, 1971; Wilson, 1971; Wilson and Meyer, 1969. LEGEND FOR FIGURE 18: | A Geographic D istribution of Amastridium ^ veliferum ^

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 2 'hT ^ "\\| ' t * -i ^ n r

\ i ' « \ •.

1

locfwJ 10*10 ?Olo

Figure 18.

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GENUS: Antillophis Maglio, 1970

TYPE SPECIES: Dromicus parvifrons Cope

CONTENT: 2 species (see LEGEND)

MORPHOLOGY: Body cylindrical with a long ta il. Maximum total length: 670 mm; Maximum t a il length: 250 mm. Head s lig h tly d istin ct from neck. Eye with large, round pupil. SCUTELLATION: Head scutes normal except temporals 1+1 or 1+2.

17 or 19 dorsal scale rows. Dorsals smooth. Each dorsal with 1 api­ cal p it. 140-200 ventral scutes. Anal divided. S5-130 caudal scutes. Caudals divided. DENTITION: 16-21+2 maxillary teeth. Postdiastemal teeth strongly enlarged. 21-26 mandibular teeth. 12-16 palatine teeth. 26-35 pterygoid teeth. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, semicapitate, with a forked sulcus, spines, and calyces. It is basically similar to that of Alsophis, but unlike that of Dromicus. Several rows of stout spines p a ra lle l the sulcus. Each branch of the sulcus terminates on a diskless apex which bears long, filifo rm calyces. There are no basal hooks, no spines between the branches of the deeply divided sulcus. Sulcus is bordered by a thick fold of spinose tissue. GEOGRAPHIC RANGE: West Indies: Cuba, Hispaniola, and nearby islands. HABITS: No information available. GENERIC RELATIONSHIPS: The osteology of Antillophis is similar to Alsophis and Dromicus. I t is closer to Alsophis in hemipenis, although it s external chara­ cters are very close to Dromicus. I t cannot be easily referred to eith er genus. The skull and hemipenis of A ntillophis are sim ilar to certain members of Lygophis. Alsophis has 2 apical pits (in some) in contrast to 1 in Antillophis and Dromicus (Maglio). REFERENCES: Boulenger, 1894; Maglio, 1970. LEGEND FOR FIGURE 19: Geographic Distribution of Species of Antillophis

X andreae parvifrons

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure Figure 19.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 76

GENUS: Apostolepis Cope, 1861

TYPE SPECIES: Elapomorphus flavotorquatus Dumeril, Bibron and Dumeril

CONTNET: 17 species (see LEGEND)

MORPHOLOGY: Body cylind rical with a short t a i l. Maximum body length: 620 mm. Maximum t a il length: 45 mm. Head not d istin ct from neck. Eye medium to tiny with a round pupil. SCUTELLATION: Head scutes normal except for internasals fused with prefrontals, no loreal; no anterior temporal; postoculars 2 or 1.

15 dorsal scale rows; dorsal scales smooth with no apical pits. 160-265 ventral scutes; ventrals rounded. Anal single or divided. 21-52 caudal scutes; caudals single or divided. DENTITION: 4-5+II maxillary teeth. Maxillary very short. Mandibular teeth subequal. VERTEBRAE: No posterior hypapophyses. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is single, noncapitate with a forked sulcus and calyces. GEOGRAPHIC RANGE: Guyana and Eastern Peru south to Argentinian, Paraguayan, and Bolivian Chaco. HABITS: Fossorial. Feeds on worms. Oviparous. GENERIC RELATIONSHIPS: No information available. REFERENCES: Amaral, 1921, 1976; Boulenger, 1896; Dunn, 1928; Hoge, 1957a; Lema, 1978. LEGEND FOR FIGURE 20: Geographic D istribution of Species of Apostolepis

ma longicaudata nigroterminata n—r. quinquelineata >*• rondoni |a| ventrimaculatus

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Figure 20.

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FIGURE 21: Geographic D istribution of Species of Apostolepis

cearensis » b a rrio i • coronata goiasensis s',, f lavotorquata .$ erythronota

FIGURE 22: Geographic D istribution of Species of Apostolepis

"I niceforoi II dorbignyi ambiniger o villaricae intermedia

assim ilis

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80 ¥ 7 0 V 60 ¥ 50 ¥ 40 ¥ Figure 22. LONG

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GENUS: Arrhyton Guenther, 1858

TYPE SPECIES: Arrhyton taeniatum Guenther

CONTENT: 7 species (see LEGEND)

MORPHOLOGY: Body is moderately elongate, cylin d rical with a medium-length t a il. Maximum length: 297 mm; maximum t a i l length: 105 mm. Head is s l­ ightly distinct from neck. Eye is small with a round pupil. SCUTELLATION: Head scutes normal except lo real may be absent.

17-19 dorsal scale rows. Dorsal scales smooth with 0-2 apical pits. 112-186 ventral scutes; ventrals rounded. Anal divided. 54-119 caudal scutes; caudals divided. DENTITION: 17-19+2 m axillary teeth. The m axillary is very short and the post- diastemal teeth are strongly enlarged. Mandibular teeth are small and subequal. Palatine and pterygoid teeth are few in number. VERTEBRAE: No posterior hypapophyses. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is either bifurcate or single with a bifurcate sulcus. It is single in A. funereus and A. polylepis, although the sulcus is deeply forked. Small spines situated along the sulcus from its base to beyond the point of branching, whereupon lateral bands of spines encircle the organ. In A. funereus, spinose folds border the sul­ cus for much of its length and fin e spinose papillae cover the apex. In A. callilaemus the hemipenis is weakly bifurcate and bears sev­ eral rows of relatively large spines along the sides of the sulcus. These grade into fin e spines basally, and the apex of each lobe has soft, spinose calyces. A. taeniatum and A. vittatum are similar. GEOGRAPHIC RANGE: Cuba, Jamaica, Isle of Pines, Puerto Rico, and American Virgin Islands. HABITS: No information available. GENERIC RELATIONSHIPS: Mainland species of Rhadinaea show remarkable s im ila rity to Arrhyton. Maglio considers i t not unreasonable to suggest a common descent for Rhadinaea and Arrhyton, although p arallel evolution may have occurred. REFERENCES: Boulenger, 1894; Buden, 1966; Cope, 1886; Dunn, 1928b, 1934; Maglio, 1970; Stejneger, 1917. LEGEND FOR FIGURE 23: Geographic D istribution of Species of Arrhyton

//callilaem us W funereus dolichrum

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n

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GENUS: Atractus Wagler, 1828 TYPE SPECIES: Atractus trllin e a tu s Wagler CONTENT: 73 species (see LEGENDS)

MORPHOLOGY: Body is cylindrical with a long or short tail. The head is not dis­ tinct from the neck, and the eye is small with a subelliptic or round pupil. SCUTELLATION: Head scutes are normal except that the loreal and preocular may be absent. The nostril is closed by a prominent nasal valve. A single pair of chin shields is enlarged. Subocular is absent. If loreal is present, both lo real and prefrontal enter eye.

15-17 dorsal scale rows. Dorsals are smooth with no apical pits. Less than 200 ventral scutes. Ventrals are rounded. Anal is sin­ gle. Caudals are divided. Like most burrowers, males average 10 fewer ventrals and 10 more caudals than females. DENTITION: 5-13 maxillary teeth on a short maxillary. The maxillary teeth dec­ rease posteriorly. The last one or two teeth are markedly shorter than the others. Mandibular teeth also decrease in size posteriorly. Both palatine and ptergyoid are toothed. VERTEBRAE: No posterior hypapophyses. The neural spine or zygapophyses are not enlarged. HEMIPENIS: Hemipenis is bilobed, noncapitate, with a forked sulcus and spines. It is bilobed only at the tips. The body of the organ with well differentiated spines may be differentiated or not. In the A. elaps and A. trilineatus groups the organ is undifferentiated: entire organ is covered with small spines arranged in longitudinal rows; spines are somewhat enlarged near the division of the sulcus. In other forms the organ is differentiated: the central spinose region is abruptly replaced at the level of the sulcus division by a series of transverse flounces that extend to the apex of the organ. Each flounce bears a ridge of small papillae along its free margin. A. badius group is undifferentiated. The hemipenis is never caly- culate. Plicae and papillae may be present. A well-developed lat­ eral naked pocket is at the base of the organ. GEOGRAPHIC RANGE: Panama to South America as fa r south as Amazonian Bolivia and South­ ern Brazil east of the Andes, and northwestern Ecuador west of the Andes; slopes and highlands of Andes in Colombia, Ecuador, and Peru. HABIT: Fossorial. GENERIC RELATIONSHIPS: Atractus appears to be closely a llie d to Geophis, but has a different hemipenial structure. In Geophis the organ is not bilobed, has no la te ra l pocket, and frequently has calyculate tips. REFERENCES: Boulenger, 1894; Dixon and Thomas, 1976b; Dunn, 1928b; Peters,^ 1960; Savage 1955, 1960.

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SPECIES of Atractus

andinus prangio badius (b) punctiventris balzani resplendens (t) biseriatus reticulatus bocki riv e ro i boettgeri roulei (t) bocourti sanguineus carrioni (t) santaemartae clarki serranus collaris (t) steyermarki crassicaudatus subbicinctum duidensis taeniatus dunni (t) torquatus ecuadorensis (t) trilineatus (t) elaps (e) trivittatus emmeli univittatus erythromelas variegatus fuliginosus vertebrolineatus gaigeae (t) ventrimaculatus guentheri vertebralis indistinctus vittatu s insipidus wagleri la n c in ii werneri la s a lle i latifrons (e) lehmanni (t) limitaneus Subgeneric Groupings (Savage, 1960) loveridgei (b) = badius group maculatus (e) = elaps group major (b) (t) = trilineatus group manizalesensis melanogaster melas A. boulengeri is not included. Its tnicheli distribution is unknown. microrhynchus (t) modestus (b) multicinctus (b) n icefo ri nigricaudus nigriventris obesus obtusirostris occidentalis (t) occipitoalbus (t) oculotemporalis pauciscutatus pamplonensis paucidens (t) peruvianus

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Atractus badius group

HEMIPENIS: D ifferen tiated: sharp demarcation between central spinose region and d is ta l flounced area. Basal plicate area w ith small spines in longitudinal rows. At level of sulcus fork is a series of scalloped, transverse flounces that extend to apex of organ. GENERIC RELATIONSHIPS: The badius group is the most primitive of Savage's three sub­ generic groups. I t is closely a llie d to the trilin e a tu s group, and only distantly related to the elaps group. LEGEND FOR FIGURE 24: Distribution of the Atractus badius group

.*'• badius 3 major a modestus O multicinctus

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85 16 165 165 1B5 105 W LONG

Figure 24.

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Atractus elaps group

HEMIPENIS: Undifferentiated: entire organ, except for short basal plicate area, is covered with small spines. Spines short, broad and of equal length. GENERIC RELATIONSHIPS: The elaps group is the most advanced of Savage's three groups. LEGEND FOR FIGURE 25: Distribution of the Atractus elaps group

X. elaps xllllatifrons

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Figure 25.

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Atractus trilineatus group

HEMIPENIS: Undifferentiated: noncapitate, entire organ, except for short basal p licate area is covered with small spines. Spines in region of sulcus division are somewhat elongate and markedly larger than either the more proximal or d istal spines. Spines decrease in size to the tip of the organ. GENERIC RELATIONSHIPS: The trilineatus group is intermediate between Savage's other two subgeneric groupings. It is similar to the badius group in • scutellation and d entition, but most closely resembles the elaps group in hemipenis. I t is thought to be derived from the badius group. LEGEND FOR FIGURE 26: Distribution of Atractus trilineatus

LEGEND FOR FIGURE 27: Distribution of Members of the Atractus trilineatus group:

M carrioni x occipitoalbus 0 roulei

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LEGEND FOR FIGURE 28: Distribution of Members of the Atractus trilineatus group

x c o lla ris 0 gaigeae a lehmanni

hi microrhynchus 3 occidentalis = paucidens t/f resplendens

LEGEND FOR FIGURE 29: Distribution of Members of the Atractus trilineatus group

x dunni e ecuadorensis

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Figure 29.

85* W 75* W 65* W

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LEGEND FOR FIGURE 30: D istribution of Species of Atractus

QC bocourti O la s a lle i * melanogaster z n icefo ri fy pamplonensis * prangio •’••• santaemartae * werneri

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Figure 30.

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LEGEND FOR FIGURE 31: D istribution of Species of Atractus

® v itta tu s • fuliginosus ■ la n c iin i o erythromelas ///* duidensis s\\ univittatus •A- riveroi = insipidus *? subbicinctum a? micheli

LEGEND FOR FIGURE 32: D istribution of Species of Atractus

crassicaudatus loveridgei

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70* W 60* W Figure 31.

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LEGEND FOR FIGURE 33: D istribution of Species of Atractus

** andinus n biseriatus o trivittatus o variegatus h vertebrolineatus * vertebralis ■ ventrimaculatus □ wagleri * obtusirostris * oculotemporalis o pauciscutatus * punctiventris 1$ sanguineus nigricaudus nigriventris

a indistinctinctus v limitaneus manizalesensis w balzani // boettgeri * c la rk i

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Figure 33.

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LEGEND FOR FIGURE 34: D istribution of Species of Atractus

* obesus ♦ melas //, guentheri •.*; serranus 'If1' torquatus

LEGEND FOR FIGURE 35: D istribution of Species of Atractus

<5) steyermarki ® bocki ^maculatus \H reticulatus emmeli

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Figure 35.

« i i i------r 85*¥ 75*W 65*W 55*W 45*W 35*W LONG

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GENUS: Calamodontophis Amaral, 1935 TYPE SPECIES: Calamodon paucidens Amaral CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body very gross with a short t a il. Maximum length 360 mm. Small head and neck. Eye very small with a vertical pupil. SCUTELLATION: Head scutes normal.

15 dorsal scale rows; dorsals smooth with 1 apical pit. 135 ventral scutes. Anal divided. 32 caudal scutes; caudals divided. DENTITION: 7+II maxillary teeth. Prediastemal teeth unusually long, grooved on outer face, more strongly so posteriorly. 16 mandibular teeth, also enlarged anteriorly. Mandibular teeth decrease posteriorly. 6 palatine teeth. 10 pterygoid teeth. VERTEBRAE: Hypapophyses not present posteriorly. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: No description available. GEOGRAPHIC RANGE: Extreme south B ra z il, Rio Grande do Sul. HABIT: No information available. GENERIC RELATIONSHIPS: Calamodontophis is a near re la tiv e of Tomodon. Both genera have long, grooved prediastemal maxillary teeth and dark mouth lining. Related genera include Tachymenis, Conophis, Tomodon, Thamnodynastes, Ptychophis, Gomesophis, and Pseudotomodon (B ailey ). REFERENCES: Amaral, 1935; Bailey, 1966a. LEGEND FOR FIGURE 36: Geographic Range of Calamodontophis paucidens

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Figure 36.

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GENUS: Carphophis Gervais, 1849 TYPE SPECIES: Coluber amoenus Say, 1825 CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body cylindrical with a medium or short ta il. Maximum total length: 355 mm. Maximum t a il length: 50 mm. Head not d istin ct from neck. Eye small with a round pupil. SCUTELLATION: Head scutes normal. Large lo real and prefrontal entering eye. No preocular; supraocular very small; upper labials 5; lower labials 6 (5).

13 dorsal scale rows. Dorsal scales smooth, without apical pits. 112-146 ventral scutes; ventrals rounded. Anal divided. 23-28 caudal scutes; caudals divided. DENTITION: 8-12 maxillary teeth. Maxillary teeth very small, subequal in size. Mandibular teeth subequal. VERTEBRAE: Hypapophyses not present posteriorly. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is slightly bilobed with a forked sulcus. Crown is non- capitate. Spines extend to the fork of the sulcus, calyces are bey­ ond. Calyces are fringed. Length: 10 caudals long. GEOGRAPHIC RANGE: South-central New England to central Alabama, southern Ohio to southern Illin o is , and south to Gulf of Mexico; southern Iowa and southeastern Nebraska to Louisiana. HABIT: Fossorial. Partial to moist earth. Almost never seen in the open, but discovered under stones, boards, in rotting logs. A woodland snake, Carphophis follows stream valleys westward. Feeds on worms, snails, slugs, and soft-bodied insects. Oviparous. GENERIC RELATIONSHIPS: No information. REFERENCES: Barbour, Harvey and Hardin, 1969; Blanchard, 1924; Boulenger, 1894; Conant, 1975; Dunn, 1928d; Wright and Wright, 1957. LEGEND FOR FIGURE 37: Geographic Range of Carphophis amoenus

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure 37.

r Further reproduction prohibited without permission, p ro d u c e d with permission otthe c o ^ h t owner. 91

GENUS: Chersodromus Reinhardt, 1860 TYPE SPECIES: Chersodromus llebmanni Reinhardt CONTENT: 2 species (see LEGEND)

MORPHOLOGY: Body cylindrical with a medium-length ta il. Maximum total length: 308 mm. Maximum t a l l length: 68 mm. Head s lig h tly d istin ct from neck. Eye medium or tiny with a vertical pupil. SCUTELLATION: Head scutes normal except no preoculars, 1 prenasal; posterior nasal concave; loreal and prefrontal entering eye; 1 prefrontal; no ant­ erior temporals.

15 or 17 dorsal scale rows. No scale row reduction. Dorsal scales striated or keeled with no apical pits. Large paired marginal pits on many if not a ll scales on anterior part of body (£. rubiventris) . 127-138 ventral scutes; ventrals rounded. Anal single. 36-43 cau­ dal scutes; caudals divided. DENTITION: 8-10 teeth on a very short maxillary. Maxillary bone does not ex­ tend beyond palatine. M axillary teeth decrease posteriorly. 9 equal-sized mandibular teeth. VERTEBRAE: Hypapophyses present on posterior vertebrae. No information on neural spine or zygapophyses. HEMIPENIS: Hemipenis is bilobed, noncapitate with a forked sulcus and spines. GEOGRAPHIC RANGE: Mexico to Guatemala (Peters). Foothills of central Veracruz, Quere- tero, Mexico (Smith). HABIT: Fossorial. £. rubiventris inhabits pine-oak forests. GENERIC RELATIONSHIPS: Chersodromus appears to be a derivative of Ninia (Downs). Cherso­ dromus and Geophis appear closely related (T aylo r). The m axillary teeth of the two genera are, however, d iffe re n t: re la tiv e ly long and slender in Chersodromus; short and heavy in Geophis (Dixon and Ketchersid). REFERENCES: Boulenger, 1893; Dixon and Ketchersid, 1969; Downs, 1967; Dunn, 1928b; Taylor, 1949. LEGEND FOR FIGURE 38: Geographic Range of Species of Chersodromus

O llebmanni • rubiventris

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Figure 38.

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GENUS: Clelia Fitzinger, 1826 TYPE SPECIES: Coluber clelia Daudin CONTENT: 6 species (see LEGEND)

MORPHOLOGY: Body cylin d rical or feebly compressed. T a il long or medium. Max­ imum body length: 2100 mm. Maximum t a il length: 340 mm. Head d istin ct from neck. Eye medium-sized or small with a ve rtic a l pupil. SCUTELLATION: Head scutes normal except preocular just reaching upper surface of head or not; 1 or 0 loreal.

17 to 19 dorsal scale rows. Dorsal scales smooth with 2 apical pits. 197-237 ventral scutes; ventrals rounded or angulate. Anal single, but may be double. 42-93 caudal scutes; caudals single or divided. DENTITION: 10-15+11 m axillary teeth. Prediastemal teeth subequal in size. Postdiastemal fangs moderately enlarged. Anterior mandibular teeth are longest. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, noncapitate with a forked sulcus. It may be spinose or spineless (B ailey). Hemipenis is bicapitate (Dowling). GEOGRAPHIC RANGE: Coasts of central Mexico to South America; Lesser A n tilles. Tropical Mexico to about 35°S latitude east of the Andes. HABIT: Terrestrial. Nocturnal. Feeds on snakes and other reptiles. Clelia feeds on good-sized venomous snakes because they are more sedentary and available (Bailey). Clelia constricts prey. Oviparous. GENERIC RELATIONSHIPS: C lelia is included in Bailey's Pseudoboini. REFERENCES: Bailey, 1967; Boulenger, 1896; Dunn, 1928b; Peters, 1960; Schmidt and Inger, 1957; Taylor and Smith, 1938. LEGEND FOR FIGURE 39: Geographic Distributions of Species of C lelia

•ijt-' c le lia .■fl* occipitolutea .

ii* i scytalina

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LEGEND FOR FIGURE 40: Geographic D istribution of C le lia equatoriana

LEGEND FOR FIGURE 41: Geographic D istribution of Species of C le lia

X bicolor rustica

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n 20 S 70 W 70 B5 W 60 W 60 LONG 75 V 40 W50 40 W Figure 41. 94

GENUS: Coniophanes Hallowell, 1860 TYPE SPECIES: Coronella fissidens Gunther CONTENT: 10 species (see LEGEND)

MORPHOLOGY: Body moderate-sized with a medium length t a i l . Maximum body length: 525 mm. Maximum t a il length: 195 mm. Head d istin ct from neck. Eye medium-sized with a round pupil. SCUTELLATION: Head scutes normal except that 9 supra]abials may be present.

17-25 dorsal scale rows. Dorsals reduced through loss of paraverte­ bral rows. Dorsals smooth, without apical p its . 111-174 ventral scutes. Anal single. Anal ridges may be present. 62-115 caudal scutes. Caudals divided. DENTITION: 8-15+II maxillary teeth. Prediastemal teeth are subequal in size. Fangs are moderately enlarged and deeply grooved. Mandibular teeth are subequal. Palatine teeth are subequal. VERTEBRAE: Hypapophyses not present posteriorly. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis varies within genus. Sulcus is always forked, although the organ may be single or bilobed, capitate or noncapitate. In the bipunctatus, quinquevittatus, fissidens, and lateritius groups the hemipenis is capitate with well developed proximal spines In the brevi- frons group the hemipenis is as above except that the most basal of hooks are enlarged. The dromiciformis and picevittis groups have the apex slightly bifurcate. In the dromiciformis group, in addition, there are 4 enlarged basal hooks and small spines. Pice­ v ittis is similar to dromiciformis except that there are no enlarged basal hooks. Ornamentation consists of about 30 spines in p ic e v ittis . In im perialis and meridanus the hemipenis is not capitate, has no hooks or spines. It is deeply bifurcate. The lobes are calyculate, but not capitate. In the everted condition there is a small, smooth area at the tip of each lobe. Inflated lateral sacs are present below the place where the sulcus forks. GEOGRAPHIC RANGE: Extreme southern U.S. and central Guerrero southward on both coasts to South America, thence southward to Peru. HABIT: Coniophanes is terrestrial,semiaquatic or sec­ retive. Mostly crepuscular or nocturnal, al­ though C. fissidens is known to be diurnal. Feeds on fishes (eels), lizard s, snakes, and frogs. C. bipunctatus is nocturnal and inhabits swamp forest. £. joanae inhabits cloud forest and mesic h i l l forest. C. fissidens is a litter snake which inhabits well-drained mesic fo rest.

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GENERIC RELATIONSHIPS: Coniophanes is closely allied to Rhadinaea, differing chiefly in having maxillary teeth grooved and in reduction in posterior scale rows. REFERENCES: Bailey, 1939; Boulenger, 1896; Dunn, 1928b; McCoy, 1969; Myers, 1969b; V illa , 1971; Zug, Hedges, and Sunkel, 1979. LEGEND FOR FIGURE 42: Geographic D istribution of the Coniophanes bipunctatus Group

:<5\ bipunctatus quinquevit tatus

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LEGEND FOR FIGURE A3: Geographic D istribution of the Coniophanes im perialis Group and Coniophanes la te ritiu s $ imperialis /ymeridanus olateritius

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LEGEND FOR FIGURE 44: D istribution of Species of Coniophanes

* fissidens p ic e v ittis

LEGEND FOR FIGURE 45: D istribution of Species of Coniophanes

• andresensis joanae /^^/dromiciformis

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GENUS: Conophis Peters, 1860 TYPE SPECIES: Conophis vittatus Peters CONTENT: 3 species (see LEGEND)

MORPHOLOGY: Body cylindrical with a medium length ta il. Maximum total length: 1.1 meters. Tail more than 20% of body length. Head slightly d istin ct from neck. Eye medium-sized with a round pupil. SCUTELLATION: Head scutes normal.

17-19 dorsal scale rows. Dorsal scale rows reduced through fusion of 3rd and 4th rows. Dorsal scales smooth with no apical p its . 141-183 ventral scutes; ventrals rounded. Anal divided. 55-89 caudal scutes; caudals divided. DENTITION: 8-12+II maxillary teeth. Large venom gland in temporal region. 15-21 mandibular teeth. Anterior mandibular teeth are longest. 6-10 palatine, and 15-19 pterygoid teeth. VERTEBRAE: No hypapophyses present posteriorly. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is s lig h tly bilobed, noncapitate with a forked sulcus and spines. Large spines are near the base, smaller spines or papillae are on flounces nearer apices; basal hooks or spines are prominent. Small apical lobes at the apices of vittatus in addition to 3-5 flounces (Dowling). £. lineatus concolor has 1 flounce. Everted length: 8 caudals (Wellman). GEOGRAPHIC RANGE: Semiarid regions of southern Mexico and Central America as far south as Costa Rica. HABIT: Terrestrial. Fossorial. Diurnal or crepuscular. Feed on frogs, toads, liza rd s , bird eggs, snakes, and mammals. Conophis does not constrict prey. Relies on venom to immobilize prey. GENERIC RELATIONSHIPS: Progenitors of Conophis may have inhabited much of North America during the Miocene, or the main stock of xenodontines reached South America in e a rlie s t T ertiary times. Formation of Panamanian and Colombian portals le f t Conophis isolated in Middle America. Two subgeneric groups: vittatus and lineatus (Wellman).. REFERENCES: Boulenger, 1896; Savage, 1966; Wellman, 1963. vT W . LEGEND FOR FIGURE 46: ^ »l v \ Geographic D istribu tion of Species of Conophis 1

"X lineatus //«y pulcher , :.c>:-vittatus \ 1

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ce

Figure 46.

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GENUS: Contia Baird and Girard 1853 TYPE SPECIES: Calamaria tenuis Baird and Girard, 1852 CONTENT: 1 species

MORPHOLOGY: Body is slender, subcylindrical with a medium-length ta il. The tail is equipped with a sharp, terminal spine. Maximum length: 19 inch­ es. The head is s lig h tly d istin ct from the neck. The eyeis med­ ium-sized with a round pupil. Snout is pointed or obtuse. SCUTELLATION: Head scutes are normal with the exception that supralabials are 6-7 and infralabials are 7.

15 dorsal scale rows. Dorsal scales have 1 apical p it. 147-186 ventral scutes. Anal divided. 27-57 caudal scutes; caudals divided. DENTITION: 11 equal-sized maxillary teeth. 14 mandibular teeth. 7-8 palatine and 12 pterygoid teeth. Last maxillary tooth is the smallest. VERTEBRAE: Hypapophyses not present posteriorly. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed (only s lig h tly ) at the very apex. The sulcus forks near the apex. The apex is calyculate fo r 1.5 caudals near the apex. The rest of the organ bears spiniferous, longitudinal ridges. The ridges tend to coalesce toward the apex. There are six ridges at the base of the organ. Distally the ridges anastmose to form calyces. 4-5 rows of calyces cover the apex. A few caly­ ces are found in the fork of the sulcus. Length: 7 caudals long. Forked portion is 1 caudal in length. Branches of forked sulcus do not run to the two lobes. GEOGRAPHIC RANGE: B ritish Colombia to southern Sierra Nevadas and central coast of California. Distribution spotty with isolated populations. HABIT: Found in woodland, grassland, and forest, usually near streams. In general prefers moist environments. Nocturnal, feeds on snails and slugs. Oviparous. GENERIC RELATIONSHIPS: Hemipenis is sim ilar to that of Carphophis (S tic k e l). REFERENCES: Stebbins, 1966; S tickel, 1951; Wright and Wright wxi957. CL, LEGEND FOR FIGURE 47: £ Geographic D istribution of Contia tenuis

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Figure 47 .

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GENUS: Crisantophls Villa, 1971 TYPE SPECIES: Crisantophls nevermanni CONTENT: 1 species

MORPHOLOGY: Body is slender. Maximum to ta l length: 828 mm. Maximum t a il length: 160 mm. Head d istin ct from neck. Eye small with a round pupil. SCUTELLATION: Head scutes normal.

19+19+17 dorsal scale rows. Dorsal scales are smooth with no apical pits. 173-183 ventral scutes. 71-89 caudal scutes. DENTITION: 13-14+11 maxillary teeth. Maxillary teeth increase posteriorly. Fangs are la te ra lly compressed and grooved throughout th e ir length. 21 or 22 mandibular teeth. 10 or 11 palatine teeth. 31-35 ptery­ goid teeth. Mandibular, palatine, and pterygoid teeth increase posteriorly in length. VERTEBRAE: Hypapophyses present on posterior vertebrae. Neural spine not enl­ arged. No information on zygapophyses. HEMIPENIS: Hemipenis is bilobed, subcylindrical, noncapitate. Basal 2/3 of hemipenis is naked. I t lacks basal flounces, hooks, or calyces. Spinules cover distal half, including lobes, which are awned. The sulcus divides near the junction of the lobes. Hemipenis is 11-15 caudals long. Sulcus forks at subcaudal 9-12. GEOGRAPHIC RANGE: V ic in ity of San Jose, Costa Rica (Rio Poas de Aserri) through cen­ tral and western Nicaragua to the vicinity of Choluteca, Honduras. 0-1400 m. HABIT: Found in arid or semiarid regions which correspond to Holdridges (1964) Tropical Dry and Tropical Very Dry Forest formations. Found in moist situations in these areas: near rivers, streams, or ponds. Feeds on fishes, tadpoles, frogs, toads, lizards, snakes (is known to be cannibalistic), and mammals. Does not constrict prey. Chews prey back to fangs. GENERIC RELATIONSHIPS: V illa puts Crisantophis (along with Rhadinaea, Erythrolamprus, Con­ ophis , and Coniophanes) into Natricidae (sensu Underwood). Crisantophis may lin k Conophis i with Rhadinaea (S c o tt). REFERENCES: N Scott, 1969; V illa , 1969, 1971; Wellman, 1963. I f LEGEND FOR FIGURE 48: X S * > - Geographic Distribution of Crisantophis nevermanni

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iue 48. Figure LAT CO 101

GENUS: Cryophis Bogert and Duellman, 1963 TYPE SPECIES: Cryophis hallbergi Bogert and Duellman, 1963 CONTENT: 1 species

MORPHOLOGY: Body is slender. Head is distinct from neck. Tail is 1/5 total body length. Eye is moderately large, with an oval, or feebly elliptical pupil. Total length: 650 mm. Tail 131 mm. Tail is 20% of total length. SCUTELLATION: Head scutes normal except for 3 supralabial which normally extends to loreal, and concave rostral which is tilted forward.

23+21+19 dorsal scale rows. Dorsal scale rows reduced through loss of paravertebrals. Dorsal scales are keeled with no apical pits. 186 ventrals; anal divided; caudals 131. DENTITION: 19-22+2 maxillary teeth. Prediastemal teeth decrease posteriorly. Prediastemal teeth become progressively shorter, stouter, and less strongly recurved from front to rear. Postdiastemal teeth are slender and enlarged. VERTEBRAE: Hypapophyses not present posteriorly. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is single, capitate with a forked sulcus. Distally the enlarged basal spines are followed by smaller spines. There are calyces on the capitulum. The sulcus extends to a depression at the terminus. The sulcus bifurcates after passing beyond the edge of the capitulum. GEOGRAPHIC RANGE: Montane habitats at the southern periphery of the Mexican plateau. Northern periphery of the Sierra de Juarez, Mexico. HABIT: Arboreal, nocturnal, found in cool cloud forest. GENERIC RELATIONSHIPS: Cryophis may be closely related to Leptodeira and Tantalophis. Leptodeira is widely dispersed. Cryophis and Tantalophis may be relicts now restricted to montane habitats. Both Cryophis and Tantalophis retain ungrooved teeth at the rear of the maxilla. Neither has advanced far on the trend toward elliptical pupils. Tantalophis has retained smooth dorsal scales with a apical pits and has proportionally smaller teeth at anterior of m axilla. I t resembles Leptodeira in this aspect. Cryophis has lost * A pits and evolved keels on dorsal scales, and T lengthened maxillary teeth. Grooved fangs, an V e llip tic a l p upil, and a simple sulcus evolved in the line that led to Leptodeira (Bogert and Duellman). REFERENCES: V J Bogert and Duellman, 1963. mmmimm j r LEGEND FOR FIGURE 49: j J Geographic D istribution of Cryophis hallbergi

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GENUS: Darlingtonla Cochran, 1935

TYPE SPECIES: Darlingtonla haetiana Cochran, 1935

CONTENT: 1 species

MORPHOLOGY: Body cylin d rical; 195 mm; t a ll 88 mm. Head small, scarcely dis­ tinct from neck; eye rather large, pupil round. SCUTELLATION: Head scutes normal with the exception of no lo real and that fir s t pair of lower labials does not meet in the mid-ventral line.

19 dorsal scale rows: dorsal scales smooth, 0 apical pits. 138 ventrals; ventrals rounded. Anal single. 45-50 caudal scutes. Pointed scale at tip of tail. DENTITION: 12-17+2 maxillary teeth. 22 subequal-sized mandibular teeth. 11 palatine, and 24 pterygoid teeth. VERTEBRAE: No hypapophyses present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bifurcate with a forked sulcus. The spines along the sides of the sulcus grade into fine spines basally. The apex is covered with calyces and fine papillae to produce a semicapitate appearance. Medial apical awns are present. GEOGRAPHIC DISTRIBUTION: Hispaniola. HABITS: Semifossorial. GENERIC RELATIONSHIPS: Darlingtonla is grouped by Maglio into his funereus assemblage. This grouping includes the species of Arrhyton. Darlingtonia does not resemble any other A ntillean or American genus. I t is probably an offshoot of ancestral Dromicus and may occupy the same niche in Haiti as Arrhyton does in Cuba (Cochran). REFERENCES: Cochran, 1941; Maglio, 1970. LEGEND FOR FIGURE 50: Geographic D istribution of Darlingtonia haetiana.

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Figure 50.

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GENUS: Diadophis Baird and Girard, 1853 TYPE SPECIES: Coluber punctatus Linnaeus CONTENT: 2 species (see LEGEND)

MORPHOLOGY: Body is cylin drical or s lig h tly compressed with a medium-length tail. Maximum total length is 749 mm. Body to ta il ratio: 0.107 to 0.261 of total length. The head is slightly distinct from the neck. The eye is medium-sized, with a round pupil. SCUTELLATION: Head scutes are normal with the exception of temporals 1+1.

13-19 dorsal scale rows. Dorsal scales are smooth with 1(0) apical p its . 126-239 ventral scutes. Anal divided. 30-77 caudal scutes; caudals divided. DENTITION: 9-21 maxillary teeth. Anterior teeth are a little smaller than post­ erior teeth, except for last two which may be enlarged and separated from the others by a short interspace. Alternate maxillary formula: 9-19+2. 16-23 subequal-sized mandibular teeth. 7-13 palatine, and 16-26 pterygoid teeth. VERTEBRAE: No posterior hypapophyses. Neural spine and zygapophyses not enlarged. HEMIPENIS: Hemipenis is slightly bilobed, elongate, nearly cylindrical. It is noncapitate with a forked sulcus and minute basal spines. The apex has calyces with low borders. The rest of the organ is covered with numerous spines of moderate size arranged in longitudinal rows. GEOGRAPHIC RANGE: Central Veracruz and Michoacan northward on the plateau into the United State. Throughout eastern North America north to about the 49th p a ra lle l, and in the fa r west to southern Washington, thence south to central Mexico. HABIT: Adapted to forested regions; not limited to any habitat. Chief requirement is shelter and slightly damp soil, associated with eco- tones. Terrestrial, feeds on worms, insects, frogs, toads, sala­ manders, lizard s, and other snakes. Oviparous. GENERIC RELATIONSHIPS: No information. REFERENCES: Barbour, 1968; Blanchard, 1942; Boulenger, 1894; Dunn, 1928b; F itch , 1975. < 1975. LEGEND FOR FIGURE 51: 7 ( j V Geographic D istribution of Diadophis punctatus ^ A LEGEND FOR FIGURE 52: [ Geographic D istribution of Diadophis dugesii V H r

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••

Figure 52.

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GENUS: Diaphorolepis Jan, 1863 TYPE SPECIES: Diaphorolepis Wagneri Jan CONTENT: 2 species (see LEGEND)

MORPHOLOGY: Maximum length: 684 mm. Body to tail ratio: 0.32 to 0.35 of total length. Eye large with round pupil. SCUTELLATION: Head scutes normal except for single prefrontal, and 9 supralabials.

21+19+17 dorsal scale rows. Reduction of dorsal scale rows through loss of 4th row. Dorsal scales smooth in D. wagneri; keeled and striated in D. laevis. Vertebral row enlarged. No apical pits. 193-197 ventral scutes. Anal single. 98-138 caudal scutes. DENTITION: Approximately 25 maxillary teeth. Last two maxillary teeth are stouter, but there is no diastema. VERTEBRAE: Hypapophyses present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed with a forked sulcus. Large spines flank the sulcus where i t bifurcates, approximately midway between the base and the distal ends of the paired lobes; the smaller spines are arranged in approximately nine rows on the base; spines extend onto lobes. GEOGRAPHIC RANGE: Darien region of Panama to western Ecuador; one doubtful record from "Eastern Ecuador." HABIT: In Choco forest (Dixon). GENERIC RELATIONSHIPS: Diaphorolepis is allied to Xenopholis and Synophis (Bogert). REFERENCES: Bogert, 1964; Dixon, 1978; Peters, 1960. LEGEND FOR FIGURE 53: Geographic D istribution of Species of Diaphorolepis

:&• laevis • wagneri

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Figure 53.

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GENUS: Dlpsas Laurenti, 1768 TYPE SPECIES: Dlpsas indica Laurenti CONTENT: 35 species

MORPHOLOGY: Body strongly compressed, with a long, slim ta il. Head distinct from neck. Eye large, usually protruding, with a vertical pupil. SCUTELLATION: Head scutes normal with the following exceptions: no preocular; temporals very irregular; supralabials 7-11; no labial in contact with postocular.

11-19 dorsal scale rows. Reduction is irreg u lar. Dorsal scales are smooth, with no apical pits. The vertebral row is enlarged in those with high scale counts. 162-200 ventral scutes; ventrals rounded, occasionally divided. Anal single. 82-145 caudal scutes; caudals divided, occasionally fused. DENTITION: 12 or more maxillary teeth. Maxillary teeth directed inwards, sub­ equal in size, and increase posteriorly. Mandibular teeth increase in length posteriorly. Palatine is toothed. Pterygoid is toothed or not. VERTEBRAE: Hypapophyses not present on posterior vertebrae. No information on neural spine or zygapophyses. HEMIPENIS: Hemipenis is s lig h tly bilobed, and capitate with a forked sulcus. The tip is s lig h tly bilobed. The proximal portion is spinose with several enlarged and prominent basal spines. The distal portion is calyculate with long papillae. The capitation is formed by a co llar at the border between the spinose and calyculate portions. GEOGRAPHIC RANGE: Southern B ra zil, Argentina, Paraguay, B o livia, and Peru north through entire remainder of South America, a ll of Central America, and Mexico as far north as Veracruz on the A tlan tic slope and Colima on the P acific slope. Range excludes highlands of north­ ern Central America and Mexico. HABIT: Arboreal. Nocturnal. Feeds on snails and slugs and soft-bodied insect larvae. GENERIC RELATIONSHIPS: Dipsas is related to Sibon and Sibynomorphus. I t represents a midpoint between these two genera. Sibon is arboreal; Sibynomorphus is not. REFERENCES: Boulenger, 1896; Dunn, 1928b; Peters, 1960; Scott, 1969; Zug, Hedges, and Sunkel, 1979.

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SUBGENERIC GROUPS OF Dlpsas

albifrons (v) articulata (a) bicolor (a) boettgeri (p) brevifacies (a) catesbyi (c) copei (c) = articulata group dimidiatus (c) =; catesbyi group elegans (o) ( i) 5 indica group ellipsifera (o) (o) =! oreas group gaigeae (a) (po) = polylepis group gracilis (a) (p) =1 p ra tti group incerta (v) (v) : : variegata group indica ( i) latifrontalis (p) latifasciata (p) leucomelas (po) longicaudatus (po) maxillaris (a) neivai (i) oreas (o) pavonia (c) perijanensis peruana (p) poecilolepis (po) polylepis (po) p ra tti (p) sanniolus santijoannis (p) schunkii (p) tamporalis (a) tenuissima (a) variegata (v) vermiculata (c) viguieri (a)

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LEGEND FOR FIGURE 54; Geographic D istribution of Dipsas articu lata Group:

artic u lata • bicolor p brevifacies |f|| dimidiata £> maxi 1 la ris tenuissima -A-viguieri

LEGEND FOR FIGURE 55: Geographic D istribution of Members of the Dipsas a rtic u lata Group • g racilis *;• temporalis

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LAT 98 W 98 o N 85 W 85 o 75* W 88 W 88 65* V 55* W 78 78 W iue 55. Figure iue 54, Figure 108

LEGEND FOR FIGURE 56:

Geographic Distribution of Dipsas gaigeae

LEGEND FOR FIGURE 57:

Geographic Distribution of Members of the Dipsas catesbyi Group

catesbyi o copei tu boettgeri //fi/ pavonia i&i perijanensis vermiculaticeps

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ct 10 S 0 10 N 85 ¥ 85 , Figure 56. Figure iue 57. Figure

5 45#V 75* ¥ 65* ¥ 5 35* ¥ 55® ¥ 109

LEGEND FOR FIGURE 58:

Geographic D istribution of the Dipsas indica Group

-.'•f indica ^ nevai

LEGEND FOR FIGURE 59:

Geographic D istribution of the Dipsas oreas Group

ellipsifera oreas

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o

Figure 59.

85 W 75 W 65 W 55 W

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LEGEND FOR FIGURE 60:

Geographic D istribution of the Dipsas polylepis Group

z/leucomelas .%'< polylepis

D. poecilolepis is not shown on this map. Its locality is V illa Bomfin, Estado de Sao Paulo, B razil.

LEGEND FOR FIGURE 61:

Geographic D istrib utio n of the Dipsas p ra tti Group

D boettgeri * latifrontalis o latifasciata • peruana x p ra tti ■ santijoannae £ schunkii

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Figure 60.

4 4

75 W 65 W 55 W Figure 61.

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LEGEND FOR FIGURE 62:

Geographic D istribution of the Dipsas variegata group

0 albifrons • incerta

LEGEND FOR FIGURE 63:

Geographic D istribution of Dipsas variegata

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Figure 63.

85 W 75 W65 W 55 W

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LEGEND FOR FIGURE 64 : Geographic D istribution of Dipsas sanniolus

LEGEND FOR FIGURE 65:

Geographic D istribution of Dipsas elegans

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I3 °U ioo'*> iue 64. Figure iue 65 Figure Z 93* W 113

GENUS: Ditaxodon Hoge, 1958 TYPE SPECIES: Philodryas taeniatus Hensel CONTENT: 1 species

MORPHOLOGY: Pupil is round. SCUTELLATION: Head scutes normal

17 dorsal scale rows. No apical pits. 170 ventral scutes. 74 caudal scutes; caudals divided. DENTITION: 12+11 maxillary teeth. Fangs are large. Size of prediastemal teeth increases posteriorly. 1-6+12-13 mandibular teeth. Pre­ diastemal mandibular teeth increase in size posteriorly. Post- diastemal mandibular teeth are smaller. VERTEBRAE: Hypapophyses not present posteriorly. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: No information available. GEOGRAPHIC RANGE: Southern B ra zil. HABIT: No information available. GENERIC RELATIONSHIPS: No information available. REFERENCES: Hoge, 1957a, 1958; LEGEND FOR FIGURE 66: Geographic Distribution of Ditaxodon taeniatus

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GENUS: Drepanoides Peracca, 1896 TYPE SPECIES: Cloelia anomala Jan CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body cylin d rical with a medium-length t a il . Head d is tin c t from neck. Eye medium-sized with a v e rtic a l pupil. SCUTELLATION: Head scutes normal with the following exceptions: 0 loreal or loreal very small; temporals 1+1 or 2+1; 6 supralabials.

15(17) dorsal scale rows. Dorsal scales smooth with two or no apical p its . Ventral scutes 150-177; ventrals rounded. Anal single. 67-84 caudal scutes; caudals divided. DENTITION: 7-10+II maxillary teeth. Many maxillary teeth with slightly enlarged, grooved posterior fangs (Peters). Maxillary teeth have no grooves (Bailey). Prediastemal teeth increase in size posteriorly Mandibular teeth subequal. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, bicapitate with a forked sulcus. It has spines, calyces, and apical awns. GEOGRAPHIC RANGE: Central Bolivia north to southern Colombia along the Andean front. HABIT: Feeds on liza rd and snake eggs. Oviparous. GENERIC RELATIONSHIPS: Drepanoides is a llie d to Manolepis. Drepanoides is the only non-opisthoglyph member of B ailey’ s Pseudoboini. Drepanoides derived from C le lia -lik e stock through modification of the fangs into sabre-like teeth and reduction of head and body scutellation. REFERENCES: B ailey ,1967; Boulenger, 1896; Dunn, 1928b; Peters, 1957b, 1960b. LEGEND FOR FIGURE 67: Geographic D istribution of Drepanoides anomalus

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n --- cvi , 82 W 72* W 62* W

Figure 67.

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GENUS: Dromicus Bibron, 1843 TYPE SPECIES: Dromicus cursor Bibron CONTENT: 11 species

MORPHOLOGY: Body cylin d rical with a medium-length t a il. Maximum to ta l length: 1000 mm. Maximum t a il length: 200 mm. Eye large, or medium­ sized, with a round pupil. SCUTELLATION: Head scutes normal with the exception of temporals 1+1 and 8 or 9 supralabials.

15, 17, or 19 dorsal scale rows. Dorsal scales smooth with 1 or no apical pits. 137-200 ventral scutes; ventrals angulate. Anal divided. 51-100+ caudal scutes; caudals divided. DENTITION: 15+2 maxillary teeth. Postdiastemal teeth strongly enlarged. 19 subequal mandibular teeth. 10 palatine, and 24 pterygoid teeth. (A ll information on dentition is for the D. melanotus group.) VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is weakly or not bilobed with a forked sulcus and apical disks. There are several rows of stout spines on the sides of the hemipenis. Small spines are also present between the diverging branches of the sulcus. The hemipenis is noncalyculate. GEOGRAPHIC RANGE: Venezuela and Colombia to Costa Rica. Guadeloupe Island south to Trinidad. 60-2100 m. HABIT: Terrestrial. Semiaquatic. Diurnal. Feeds on frogs. GENERIC RELATIONSHIPS: Dromicus is morphologically continuous with Leimadophis (M aglio). Dromicus related to Leimadophis, Lygophis, and Xenodon (Scott). REFERENCES: Buden, 1966; Maglio, 1970; Schwartz and Thomas, 1960; Scott, 1969. LEGEND FOR FIGURE 68: Geographic D istribution of Species of Dromicus melanotus group

• cursor O j u l i a e A ornatus * perfuscus

LEGEND FOR FIGURE 69: Geographic D istribution of Species of Dromicus

•$.. epinephalus melanotus (melanotus group)

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Figure 69 .

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LEGEND FOR FIGURE 70: D istribution of Species of Dromicus

x reginae y. taeniatus

LEGEND FOR FIGURE 71: D istribution of Dromicus almadensis

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H cc 3 a

75 W 65 W 55 W 45 W 35 W LONG Figure 71.

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GENUS: Elapomojus Jan, 1862 TYPE SPECIES: Elapomorphus (Elapomojus) dimidiatus Jan CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body la te ra lly compressed with a short, obtuse t a i l . Maximum length: 580 mm. Maximum t a il length 40 mm. Head not d istin ct from neck. Eye very small with a round pupil. SCUTELLATION: Head scutes normal except no internasals, temporals 1+1; 6 supra- labials, 2 and 3 enter eye, 5 very small; 5 infralabials in con­ tact with chin shields; internasals fused with prefrontals; 3 pairs of chin shields; 1 pre- and 1 postocular.

15 dorsal scale rows. Dorsal scales smooth, no apical pits. 246 ventral scutes; ventrals rounded. Anal divided. 26 caudal scutes; caudals divided. DENTITION: 4-5+II maxillary teeth. Maxillary short with very small teeth. Fangs large. Mandibular teeth subequal. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: No information available. GEOGRAPHIC RANGE: B razil. HABITS: No information available. GENERIC RELATIONSHIPS: Elapomojus is known only from the type specimen, which is no longer extant. REFERENCES: Boulenger, 1896. LEGEND FOR FIGURE 72: Geographic D istribution of Elapomojus dimidiatus

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75 W 65 W 55 W 45 W 35 W LONG Figure 72.

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GENUS: Elapomorphus Wiegmann, 1843 TYPE SPECIES: Calamarla Blumii Schlegel CONTENT: 8 species (see LEGEND)

MORPHOLOGY: Cylindrical body with a short tall. Maximum total length: 1180 mm. Maximum tall length: 120 mm. Head not distinct from neck. Eye small or tiny with a vertical or round (Boulenger) pupil. SCUTELLATION: Head scutes normal with the exception of fused prefrontals in some, 2 prefrontals in others; in some rostral separates internasals.

15 dorsal scale rows. Dorsal scales smooth with no apical pits. 176-240 ventral scutes; ventrals rounded. Anal divided. 21-45 caudal scutes; caudals divided. DENTITION: 4-5+II maxillary teeth. Maxillary very short. Mandibular teeth sub­ equal in length. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed with a forked sulcus. It is covered with deli­ cate spines which become smaller towards the apices. Hemipenis is short: extends to 7th caudal. GEOGRAPHIC RANGE: Tropical and subtropical lowland rainforests in South America from northeastern Brazil to Argentina. HABITS: Semifossorial. Nocturnal. Feeds on worms and insects. Found in underground (0.8-1.0 meters) galleries of large nests of neotropical leaf cutting ants. Have a bite that is deadly to humans. GENERIC RELATIONSHIPS. No Information. REFERENCES: Boulenger, 1896; Dunn, 1928b; Lema, 1970, 1978a, 1978c, 1979b; Scolaro, 1979. LEGEND FOR FIGURE 73: Geographic Distribution of Species of Elapomorphus bilineatus ■ lepidus ^ mertensi • punctatus > m tricolor \ LEGEND FOR FIGURE 74: Geographic Distribution of Species of Elapomorphus •'•ft nasutus • quinquelineatus ^vucheri

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GENUS: Enulius Cope, 1871 TYPE SPECIES: Enulius murinus Cope CONTENT: 3 species (see LEGEND)

MORPHOLOGY: Body is cylindrical with a long tail. Maximum total length: 340 mm. Maximum t a i l length: 140 mm. Head scarcely d istin c t from neck. Eye with a round pupil. SCUTELLATION: Head scutes normal with the exception of no preoculars.

13-17 dorsal scale rows. Dorsal scales smooth with 1(2) apical pits. Ventral scutes 129-216. Anal divided. 82-105 caudal scutes; caudals divided. DENTITION: 3-4+2 maxillary teeth. Maxillary teeth increase in size posteriorly. Postdiastemal teeth are flattened, relatively enormous, and ungrooved. VERTEBRAE: Hemipenis is bilobed, noncapitate with a forked sulcus. The degree of bilobation varies from slightly to distinctly bilobed. Sulcus forks at the extreme d is ta l end, or in the middle of the basal por­ tion. There are no calyces. Organ bears minute, uniform spines. GEOGRAPHIC RANGE: Central-western Mexico (Michoacan, Sinaloa) south to Colombia. 0-1450 m. HABITS: Fossorial. Feed on reptile eggs (Scott). GENERIC RELATIONSHIPS: Enulius is remarkably isolated. No American snake is known with sim­ ila r hemipenes, or similar dentition. None of the other small Amer­ ican ground snakes has such a long t a i l , or has any scale p its . E. flavitorques is the ancestral population of the genus. EL sclateri and E. oligostichus are somewhat parallel, but unrelated peripheral derivatives of the stock (Smith, Arndt, Sherbrook). Hemipenes and scale ornamentation similar to those of Geophis (Scott). REFERENCES: Boulenger, 1894, 1896; Cope, 1886; Dunn, 1938; Scott, 1969; Smith, Arndt, and Sherbrooke, 1967. LEGEND FOR FIGURE 75: Geographic D istribution of Species of Enulius

!®f lavitorques /^/oligostichus ^ s c la t e r i 7

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107 W 97 W 77 W

Figure 75.

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GENUS: Eridiphas Leviton and Tanner, 1960 TYPE SPECIES: Hypsiglena slevini Tanner CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Head distinct from neck. Eye large with a vertical pupil. Maximum length: 424 mm. Maximum t a il length: 70 mm. The t a il is 16.5 to 18.9% of the total body length. SCUTELLATION: Head scutes are normal except that the ro stral is twice as broad as i t is deep.

23 dorsal scale rows. Dorsal scales smooth with 1 apical pit. 184- 190 ventral scutes. Anal divided. 55-68 caudal scale rows. Caudals divided. DENTITION: 12+2 maxillary teeth. Maxillary teeth increase in size posteriorly. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is single, capitate with a simple sulcus. A small patch of enlarged spines are present near the distal end, followed by a capitulum of calyces. Length: 10 subcaudals long. GEOGRAPHIC RANGE: Baja C alifo rn ia, Mexico. HABITS: No information. GENERIC RELATIONSHIPS: Eridiphas is intermediate between Hypsiglena and Leptodeira. It probably represents a relict of an early ancestral stock from which these genera subsequently diverged. E. slev in i must have been an early invader of the Baja Peninsula. Eridiphas is a relict of a once more widespread group of western Mexican snakes. The ancestral population of Eh slevini must have been isolated on Baja after the Gulf of California formed in the late Miocene or early Pliocene (Leviton and Tanner). REFERENCES: Leviton and Tanner, 1960; Tanner, 1943, 1966. LEGEND FOR FIGURE 76: Geographic D istribution of Eridiphas slevini

I

•MM

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure 76.

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GENUS: Erythrolamprus Wagler, 1830 TYPE SPECIES: Coluber agilis Linnaeus CONTENT: 6 species (see LEGEND)

MORPHOLOGY: Body la te ra lly compressed with a medium-length t a i l . Maximum body length: 780 mm. Maximum t a i l length: 105 mm. Head scarcely dis­ tin c t from neck. Eye medium-sized with a round pupil. SCUTELLATION: Head scutes normal except fo r 1 pre- and 2 postoculars; temporals 1+2(1+1); 7 upper lab ials.

15-25 dorsal scale rows. Dorsal scales smooth with no apical pits. 172-204 ventral scutes; ventrals rounded. Anal divided. 38-61 cau­ dal scutes. Caudals divided. DENTITION: 10-15+11 m axillary teeth. M axillary teeth subequal in size; fangs feebly enlarged. VERTEBRAE: Hypapophyses not present posteriorly. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, and disked with a forked sulcus and spines. GEOGRAPHIC RANGE: Erythrolamprus has a wide d istrib u tio n in South America. Found in a ll of Central America from Costa Rica to northwestern Peru on the Pacific slope. Including Colombia, Venezuela, and Guyanas to south­ ern Brazil, Bolivia, Peru (east of Andes) and Argentina. 0-1450 m. HABITS: Erythrolamprus is terrestrial, secretive, and diurnal. Found in rain­ forests and xeric conditions, in northern forests and choco forests (Dixon). I t feeds on frogs, liza rd s , amphibians, eels, snakes, and rodents. It is oviparous. GENERIC RELATIONSHIPS: Erythrolamprus is associated with Liophis by Dunn (Scott). REFERENCES: Boulenger, 1896; Dixon, 1979; Dunn, 1928b; Roze, 1959, 1966; Savage, 1966; Scott, 1969. LEGEND FOR FIGURE 77: Geographic Distribution of Species of Erythrolamprus

/& aesculapii $T mimus sj

LEGEND FOR FIGURE 78: Geographic Distribution of Species of Erythrolamprus

X. baupertherisii |p)bizona jg; guentheri pseudocorallus

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> ------i— 85'W 75* W 65* W 55* W 45* V LONG Figure 77.

Figure 78. 77* W 67* W

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GENUS: Farancia Gray, 1842 TYPE SPECIES: Farancia abacura Gray CONTENT: 2 species (see LEGEND)

MORPHOLOGY: Body is cylin d rical. Maximum length: 1020 mm. Maximum t a i l length: 150 mm. Head not d istin ct from neck. Eye small with a round pupil. SCUTELLATION: Head scutes normal with the exception of : single or no preocular; loreal and prefrontal enter eye; nostril directed upwards; internasals 2 or 1.

19 dorsal scale rows. Dorsal scales smooth with no apical pits. 157— 206 ventral scutes; ventrals rounded. Anal divided. 34-55 caudal scutes. Caudals divided. DENTITION: 15-18 maxillary teeth, a ll subequal in size. Mandibular teeth subequal in size. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, semicapitate, with a forked sulcus. F. erytro- gramma has apical calyces and a few enlarged basal spines. _F. abacura has numerous enlarged spines. Length: 9-12 caudals long. GEOGRAPHIC RANGE: Potomac drainage of southern Maryland, southward through coastal plain into north-central Florida and westward to eastern Louisiana. HABITS: Farancia is aquatic. It feeds on eels, Siren, and Amphiuma. GENERIC RELATIONSHIPS: Farancia is similar to Pseudoeryx plicatilis in anatomical features and habits. Both genera are derived from a now-extinct Mexican anc­ estor (Neill). REFERENCES: Boulenger, 1894; Dunn, 1928b; N e ill, 1964. LEGEND FOR FIGURE 79: Geographic D istribution of Species of Farancia

rz abacura erytrogramma

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure 79

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GENUS: Geophls Wagler, 1830 TYPE SPECIES: Catostoma chalybeus Wagler CONTENT: 36 species (see LEGEND)

MORPHOLOGY: Body cylindrical with a short or medium-1ength tail. Maximum total length: 400 mm. Tail is less than \ of total length. Head not dis­ tinct from neck. Eye is tiny or variable, with either a round or a vertical pupil. SCUTELLATION: Head scutes are variable. Some have normal colubrid head scales; others lack supraoculars; some have large rostral; some lack inter­ nasals; some lack anterior temporal; preoculars may be missing; lor- eal and preocular enter eye.

15 or 17 dorsal scale rows. Dorsal scales smooth or keeled. Apical pits present (Boulenger). No apical pits (Dunn). 115-185 ventral scutes. Anal single. 19-66 caudal scutes; caudals divided. DENTITION: 6-17 maxillary teeth. First and last two teeth shorter than the rest, which are subequal in size. Mandibular teeth are also subequal. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis shows great variation. It can be bilobed, or single with a forked sulcus. It can be capitate, semicapitate, or noncapitate. The base of the hemipenis has little variation. It bears numerous minute spinules, a few large spines, and a naked pocket. Large sp­ ines are generally in the distal half of the basal region. The cen­ tral portion of the hemipenis is variable. It has a variable num­ ber of large or medium-sized spines and hooks arranged as a collar around the organ. The spines are largest immediately lateral to the sulcus. The distal portion is the most varied: capitate in G. chalybeus, omiltemanus, semidoliatus, and sieboldi. It is less distinctly capitate in the dubius and latifrontalis groups. The G. championi group is not capitate. GEOGRAPHIC RANGE: From Tamaulipas and Chihuahua to northwestern Colombia. HABITS: Fossorial. GENERIC RELATIONSHIPS: Geophis is derived from Atractus (whose hemipenis has a deeply bifurcate sulcus and even a cleft apex) (Downs). Derived from Ninia, Geophis gave rise to Atractus (Dunn). REFERENCES: Boulenger, 1894; Dixon, 1974; Downs, 1967; Duellman, 1959; Dunn, 1928b; Johnson, 1979; Smith, 1942d; Smith and Holland, 1969; Smith and Smith, 1964.

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LEGEND FOR FIGURE 80:

Geographic D istribution of the Geophis championi Group

;C>'. championi ^ godmani ^^ruthveni

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iue 80. Figure LAT 5 W 95 85 W 85 75 W 75 125

LEGEND FOR FIGURE 81: Geographic D istribution of Geophis omiltemanus Group

9 incomptus o'? isthmicus A maculiferus x omiltemanus Established localities are between 1600 and 2500 meters.

LEGEND FOR FIGURE 82: Geographic D istribution of Geophis la tifro n ta lis Group

o blanchardi • latifrontalis •® mutitorques

Established lo c a litie s are in humid montane forests between 1000 and 2600 meters.

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llOTiO 25 N itoVo iue 81. Figure lotAo ^ ° ? » 5 U P 0 1 126

LEGEND FOR FIGURE 83: Geographic D istribution of Geophis semidoliatus Group

A cancellatus ® laticinctus • semidoliatus

LEGEND FOR FIGURE 84: Geographic Distribution of Geophis chalybeus Group

® aquilonaris ■/<•:• bicolor ■ chalybeus & dugesi ■* nigrocinctus o tarascae

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25 N iue 83. Figure iue 84. Figure 127

LEGEND FOR FIGURE 85: Geographic D istribution of Members of Geophis sieboldi Group

• brachycephalus B' hoffmanni o zeledoni

LEGEND FOR FIGURE 8 6 : Geographic Distribution of Members of Geophis sieboldi Group

nasalis petersii • sallaei A sieboldi

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Figure Figure iue 85. Figure n 6 8 . 85° W 75° W 128

LEGEND FOR FIGURE 87: Geographic Distribution of Geophis dubius Group /ft fulvoguttatus ~SZ immaculata .£>•; rhodogaster

LEGEND FOR FIGURE 8 8 : Geographic D istribution of Geophis dubius Group 1®) carinosus .ip;, dubius

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85* W 75® W Figure 87.

Figure 88

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LEGEND FOR FIGURES 89 and 90: Geographic D istribution of Geophis Species Not Assigned to a Subgeneric Group

duellmani

albiventris dunni

longiceps is not shown. Its locality is given as San Jose Acateno, Venezuela.

G. rostralis is not shown. Its locality is "uncertain, possibly Western Oaxaca."

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure 89.

SOW 80 W Figure 90.

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GENUS: Gomesophis Hoge and Mertens, 1959 TYPE SPECIES: Tachymenis brasillensis Gomes CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Head not d istin ct from neck. Pupil round. SCUTELLATION: Head scutes normal.

No information as to number of dorsal scale rows. Apical pits are present. 127-147 ventral scutes. DENTITION: 13-15+11 maxillary teeth. Maxillary teeth increase posteriorly. 10-14 palatine teeth. 20-24 pterygoid teeth. No information on mandibular teeth. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is bilobed, but not deeply so. Some have small basal spines, others have large basal spines. Tip is spinose like the hemipenis of Tachymenis, but lacks apical "scheibe". GEOGRAPHIC RANGE: Brazilian states of Minas Gerais, Sao Paulo, Parana, and Rio Grande do Sul. HABITS: No information available. GENERIC RELATIONSHIPS: Gomesophis is intermediate between Tachymenis and Coniophanes (Hoge and Mertens). REFERENCES: Hoge and Mertens, 1959. LEGEND FOR FIGURE 91: Geographic Distribution of Gomesophis b rasiliensis

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 50 W LONG Figure 91.

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GENUS: Hellcops Wagler, 1830 TYPE SPECIES: Coluber carinlcaudus Wied CONTENT: 14 species (see LEGEND)

MORPHOLOGY: Body is cylindrical with a medium length ta il. Maximum length is 1010 mm. Maximum t a i l length is 180 mm. Head is s lig h tly d is tin c t from neck. Eye is medium-sized or small with a round pupil. SCUTELLATION: Head scutes are normal except: single internasal; and upward-dir­ ected nostrils.

17-25 dorsal scale rows. Dorsal scales smooth or keeled or striated. No apical pits. One has anterior scales smooth, or feebly keeled while the posterior scales are strongly keeled. 102-155 ventral scutes; ventrals are rounded 43-94 caudal scutes. Anal divided. DENTITION: 18-25 maxillary teeth. Diastema present (Boulenger). No diastema (Dunn). M axillary teeth increase in length posteriorly, subequal in size. Mandibular teeth subequal in size. VERTEBRAE: Hypapophyses present on posterior vertebrae. Neural spine not enlarged. HEMIPENIS: Hemipenis is bilobed, calyculate, spinose, with a forked sulcus and no apical disks. Intrageneric variation as to bilobation (shallow to deep). The greater part of the organ is usually spinose with a few weakly developed calyces adorning the truncated apical lobe in some. In others the organ is semicapitate and entirely spinose, the very small spines in the apical region are situated along fleshy ridges, some of which are transverse, other ridges are longitudinal. No calyces in some species. GEOGRAPHIC RANGE: Colombia throughout South America to Argentina. HABIT: Helicops is aquatic and feeds on fishes. It is oviparous and may be be facultatively ovoviviparous (Rossman, 1973). GENERIC RELATIONSHIPS: Not closely related to Hydrops or Pseudoeryx (Rossman). REFERENCES: Amaral, 1976; Boulenger, 1893; Dunn, 1928b; Peters, 1960a; Rossman, 1968, 1973b; Rossman and Dixon, 1975. LEGEND FOR FIGURE 92: Geographic D istribution of Helicops leopardinus and H. trivlttatus leopardinus trivittatus

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n

^ 85* IB* fl65* 165* 1ft 5* 105* V LONG Figure 92.

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LEGEND FOR FIGURE 93: Geographic Distribution of Species of Helicops n // angulatus o d a n ie lli = hogei

h i y a c u

LEGEND FOR FIGURE 94: Geographic D istribution of Species of Helicops

Cp/carinicaudus gome si *• hagmanni ~ r modestus c22>pictiventris

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Figure 94. 4 5 W75 W55 W 45 W75 35 V LONG

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GENUS: Heterodon Latreille, 1802 TYPE SPECIES: Heterodon platyrhlnos Latreille CONTENT: 3 species (see LEGEND)

MORPHOLOGY: Body stout, subcylindrical with a short ta il. Head scarcely distinct from neck. Eye medium-sized with a round pupil. SCUTELLATION: Head scutes normal with the exception of the sharply turned-up ros­ tral; temporals 2+3 or 4+5; loreal missing or multiple; 1-14 azy- gous scales.

23-27 dorsal scale rows. Dorsal scales keeled with apical pits. 114-156 ventral scutes; ventrals rounded. Anal divided. 27-60 caudal scutes; caudals divided. DENTITION: 6-11+2 maxillary teeth. Maxillary very short. Postdiastemal teeth enlarged, but not grooved. Maxillary teeth increase in length post­ eriorly. Mandibular teeth subequal. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spines not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, semicapitate, with a forked sulcus. It has spines and d is ta l calyces. GEOGRAPHIC RANGE: New Hampshire west to Montana and south through the Gulf States and northern Mexico. HABIT: Terrestrial. Diurnal. Feeds on frogs, toads, salamanders, lizards, snakes, birds, mammals, and insects. GENERIC RELATIONSHIPS: No information available. REFERENCES: Boulenger, 1894; Dunn, 1928b; Edgren, 1952, 1955. LEGEND FOR FIGURE 95: Geographic D istribution of Species of Heterodon

naslcus \\ platyrhinos ollilUS

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure 95.

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GENUS: Hydrodynastes Fitzinger, 1843 TYPE SPECIES: Elaps Schrankii Wagler CONTENT: 2 species (see LEGEND)

MORPHOLOGY: Body is cylin d rical with a long t a i l . Maximum length is more than 2 meters. Head moderately d istin ct from neck. Eye is medium (H. gigas) or small (H. bicinctus) with a round pupil. SCUTELLATION: Head scutes are normal. Suboculars are present.

19 or 21 dorsal scale rows. Scale rows reduced posteriorly through loss of paravertebrals. Dorsal scutes are smooth with apical pits (H. gigas), or without apical p its (H. bicinctus) . 153-192 ventral scutes; ventrals rounded. Anal single. 60-94 caudal scutes; caudals divided. DENTITION: 12-17+2 m axillary teeth. Postdiastemal teeth are strongly enlarged, but ungrooved. Mandibular teeth are subequal. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spines not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, semicapitate, with a forked sulcus. It has spines and distal calyces. GEOGRAPHIC RANGE: Southern B ra zil, eastern B olivia, Paraguay, and northern Argentina. Guianas, Amazonian region of B ra zil, Colombia and Venezuela. HABIT: Hydrodynastes is aquatic and feeds on fishes, frogs, and toads. Oviparous. GENERIC RELATIONSHIPS: Hydrodynastes is related to Alsophis and Heterodon (Dowling). REFERENCES: Amaral, 1976; Boulenger, 1894; Dixon, 1978; Dowling, 1970; Dunn, 1928b. LEGEND FOR FIGURE 96: Geographic D istribution of Species of Hydrodynastes

bicinctus • gigas

*

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Figure 96.

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GENUS: Hydromorphus Peters, 1895 TYPE SPECIES: Hydromorphus concolor Peters CONTENT: 3 species (see LEGEND)

MORPHOLOGY: Body cylindrical, elongate, with a short ta il. Maximum length: 850 mm. Maximum t a i l length: 86 mm. Head scarcely d istin ct from neck. Eye very small with a round pupil. SCUTELLATION: Head scutes normal except 1-2 internasals; 1-3 prefrontals; preocular may be absent.

13-19 dorsal scale rows. Dorsal scales smooth with apical pits. 164-180 ventral scutes; ventrals rounded. 31-52 caudal scutes. Anal divided. DENTITION: 14 maxillary teeth. Maxillary teeth increase posteriorly. No dia­ stema. Mandibular teeth subequal. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: No information available. GEOGRAPHIC RANGE: Lowland of central Panama, moderate elevations on the Pacific versant of western Panama; low and moderate elevations of Costa Rica and Hond­ uras. H. c la rk i and H. dunni known only from type lo c a lity . H. clarki may be synonym of H. concolor and H. dunni. HABIT: Aquatic. Nocturnal. Probably feeds on fish and frogs (Scott). 0-1500 m. GENERIC RELATIONSHIPS: Hydromorphus may be a derivative of the widespread aquatic genus, Tretanorhinus. REFERENCES: Boulenger, 1894; Dunn, 1928b; Nelson, 1966; Savage, 1966; Scott, 1967. LEGEND FOR FIGURE 97: Geographic D istribution of Species of Hydromorphus

%i c la rk i concolor .■* dunni a

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Figure 97.

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GENUS: Hydrops Wagler, 1830 TYPE SPECIES: glaps mart11 Wagler CONTENT: 2 species (see LEGEND)

MORPHOLOGY: Body cylindrical with a short ta il. Maximum total length: 780 mm. Maximum t a i l length: 110 mm. Head not d istin ct from neck. Eye tiny with a round pupil. SCUTELLATION: Head scutes normal with the exception of nostril directed upward; only 4th supralabial in contact with eye; internasals fused into single scale.

19+17+15 dorsal scale rows. Reduction of scale rows through loss of 3rd row. Dorsal scales smooth with no apical p its . 148-191 ven­ tr a l scutes; ventrals rounded. Anal single, or divided. 40-76 caudal scutes; caudals divided. DENTITION: 12-14 maxillary teeth. Maxillary teeth increase posteriorly. No diastema. Mandibular teeth 13-15, subequal in size. 17-20 ptery­ goid teeth. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, noncapitate with a forked sulcus. Sulcus bifurcates above middle of organ. Several longitudinal rows of large spines, 12 spines in each row. Rows extend from base to apex, where appear a few calyces and smaller spines. H. m artii has a sha­ llow ly bilobed, short organ which is 6 subcaudals long. The greater part of the organ is spinose with a re la tiv e ly few, weakly developed calyces adorning the truncated apical lobes. GEOGRAPHIC RANGE: Northern South America east of the Andes south to Paraguay. HABIT: Hydrops is aquatic and nocturnal. It feeds on fishes and frogs. GENERIC RELATIONSHIPS: Hydrops is related to Helicops. Helicops and Hydrops may both be related to Pseudoeryx (Roze). REFERENCES: Boulenger, 1894; Dunn, 1928b; Peters, 1960a; Rossman, 1973b; Roze, 1957a, 1957b. LEGEND FOR FIGURE 98: Geographic D istribution of Species of Hydrops

• m artii Q triangularis

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Figure 98.

*

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GENUS: Hypsi8len« Cope, 1860 TYPE SPECIES: Hypsiglena ocbrorhynchus Cope CONTENT: 2 species (see LEGEND)

MORPHOLOGY: Body is slender, cylindrical, with a short, very specialized tall. Maximum length seldom reaches 700 mm. Tail is usually h of the body length. The head is distinct from the neck. The eye is very small, with a vertical pupil. SCUTELLATION: The head scutes are normal vith the exception of nasals distinct or united above the nostrils; 2-3 pre- and 1-3 postoculars; 1-2+3 temporals.

17-23 dorsal scale rows. Dorsal scales are smooth with one apical pit. 154-204 ventral scutes. Anal divided. Males have supranal spines and keeled scales above the vent. 36-71 caudal scutes; caudals divided. DENTITION: 7-14+2 maxillary teeth. The prediastemal teeth are subequal in size. The postdiastemal teeth are ungrooved and fang-like. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spines are not enlarged. Zygapophyses are not enlarged. HEMIPENIS: The hemipenis is bilobed (Dowling) or single with a simple sulcus. The organ is short. Its base is nude with spinules distally. There is a medial band of short, curved spines below the capitation. Large papillate calyces are distal to the capitation. GEOGRAPHIC RANGE: Throughout arid and semi-arid parts of the United States from Wash­ ington and Kansas southward over the Mexican Plateau on the Pacific coast of Mexico, as well as on the Baja Peninsula. HABIT: Nocturnal. Feeds on lizards. Oviparous. GENERIC RELATIONSHIPS: Closely related to Leptodeira and Eridiphas (Duellman; Tanner). Old inhabitant of Baja California (Tanner). REFERENCES: Boulenger, 1894; Dixon, 1965; Duellman, 1958a, 1966a; Peters, 1956; Tanner, 1966; Tanner and Banta, iTbv 1962. . LEGEND FOR FIGURE 99: | Geographic Distribution of Species of Hypslglena iMaffinis **** torquata • f

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure 99.

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GENUS: Hypslrhynchus Guenther, 1858 TYPE SPECIES: Hypslrhynchus fferox Guenther CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body is cylindrical with a medium-length ta il. Maximum total length: 700 mm. Maximum t a il length: 140 mm. Head is s lig h tly d istin c t from neck. Eye is large and buldging, with an oval or irregularly round pupil. SCUTELLATION: Head scutes normal with the exception of the ro stral which forms an acute angle with the top of the head; loreal is absent in some popu­ lations; prefrontals may be fused.

19 dorsal scale rows. Dorsal scales smooth with 1 apical pit. 166- 177 ventral scutes; ventrals rounded. 72-88 caudal scutes; caudals divided. Anal divided. DENTITION: 13-15 maxillary teeth. Maxillary teeth increase slightly in length posteriorly. 19-20 mandibular teeth; anterior mandibular teeth long­ est. 7 palatine and 17-19 pterygoid teeth. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed and semicapitate. Sulcus forks near the base of the organ and each branch extends to the tip of one lobe of the deeply bifurcated apex. Several rows of longitudinally arranged spines are present along the middle half of its length. These grade into numerous smaller spines d is ta lly . The base may be nude or have long plicae. The sulcus is bordered by a fringe of folded tissue with modest-sized, closely spaced spines that grade into smaller ones distally. On the apex of each lobe, a reticulate network of tissue surrounds the sulcus, with moderate to long, filifo rm papil­ lae. Calyces grade into surrounding tissue. Has long apical pap­ illa e . GEOGRAPHIC RANGE: Hispaniola HABIT: No information available. GENERIC RELATIONSHIPS: Hypslrhynchus is sim ilar to Alsophis a te r. I t may be the result of dispersal from Jamaica to Hispaniola (Maglio). REFERENCES: Boulenger, 1894; Dunn, 1928a; Maglio, 1970; Schwartz, 1969. LEGEND FOR FIGURE 100: Geographic D istribution of Hypslrhynchus ferox

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LAT o iue 100. Figure 2 CO ; * W 5 7 139

GENUS: Ialtris Cope, 1862 TYPE SPECIES: Philodryas dorsalis Guenther, 1858 CONTENT: 2 species (see LEGEND)

MORPHOLOGY: Body is cylindrical with a long ta il. Maximum length: 1090 mm. Maximum t a il length: 350 mm. Head d istinct from neck with a d ist­ inct canthus ro s tra lis . Eye large with a round pupil. SCUTELLATION: Head scutes are normal.

19 dorsal scale rows. Dorsal scales smooth with 0-2 apical pits. 180-188 ventral scutes; ventrals rounded. Anal divided. 102-110 caudal scutes; caudals divided. DENTITION: 14+11 maxillary teeth. Last prediastemal teeth large and fang-like, but ungrooved. 5-6 mandibular teeth. Anterior mandibular teeth increase in length and are followed by a toothless space. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed and noncapitate with a forked sulcus. I t is very long and ridged with numerous folds. It has an apical orna­ ment of weakly developed flounces. Spines are also present. GEOGRAPHIC RANGE: Hispaniola. HABIT: No information available. GENERIC RELATIONSHIPS: Ialtris dorsalis is not very close to any other Antillean species, as far as can be determined from its present morphological speciali­ zations. It is a distinct genus. In most characteristics it is sim­ ila r to Alsophis and may have been derived from that genus on Hispaniola (Maglio). REFERENCES: Boulenger, 1896; Maglio, 1970. LEGEND FOR FIGURE 101: Geographic Distribution of Species of Ia lt r is

| xldorsalis • * parishi

OMR I «MI

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Figure 101.

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GENUS: Imantodes Dumerll and Bibron, 1853 TYPE SPECIES: Colubet cenehoa Linnaeus CONTENT: 5 species (see LEGEND)

MORPHOLOGY: Body Is slender, strongly compressed with a long t a l l . Maximum to ta l length: 1100 mm. Maximum t a il length: 340 mm. Head is dis­ tinct from neck. Eye is large with a vertical pupil. SCUTELLATION: Head scutes are normal with the exception of 1-3 preoculars.

17+15+13 dorsal scale rows. Dorsal scales are smooth with no apical pits. The vertebral scales are 2 to 4 times as wide as the para- vertebrals. 214-267 ventral scutes; ventrals rounded. Anal is single or divided. 109-175 caudal scutes; caudals divided. DENTITION: 12-18+2 maxillary teeth. Maxillary teeth equal in size. Anterior mandibular teeth are longest. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is single with large spines proximally and calyces d is ta lly . It has a simple sulcus and is capitate. GEOGRAPHIC RANGE: Mexico through Central America to northwestern Ecuador west of Andes to Paraguay, Argentina, and Bolivia east of the Andes. 0-1530 m. HABIT: Imantodes is arboreal, nocturnal, or crepuscular. I t may hide in bromeliads by day. It feeds on frogs and lizards, especially Anolis. GENERIC RELATIONSHIPS: Imantodes is probably a highly specialized derivative of Leptodeira (S c o tt). REFERENCES: Boulenger, 1986; Cope, 1861; Fukada, 1964; Henderson and Nickerson, 1976; Scott, 1969; Zug, Hedges, and Sunkel, 1979; Zweifel, 1959. LEGEND FOR FIGURE 102: Geographic D istribution of Species of Imantodes x gemmistratus \Yy inornatus °So tenuissimus

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LEGEND FOR FIGURE 103: Geographic Distribution of Imantodes lentiferus

LEGEND FOR FIGURE 104: Geographic D istribution of Imantodes cenchoa

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Figure 103.

no

o

98 *8 178 168 158 148 138 1

Figure 104 LONG

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GENUS: Leimadophls Fitzinger, 1843 TYPE SPECIES: Coronella almadensls Fitzinger CONTENT: 11 species (see LEGEND)

MORPHOLOGY: Body is cylindrical. Head is slightly distinct with a round pupil. SCUTELLATION: Head scutes are normal.

19-15 dorsal scale rows. Dorsal scales are smooth with 1 apical pit. 132-182 ventral scutes; ventrals are rounded. Anal divided. 45- 75 caudal scutes; caudals are divided. DENTITION: 18-23+2 m axillary teeth. Postdiastemal teeth are two times the size of the others, but not grooved. Mandibular teeth are subequal-sized. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is bilobed and disked with a forked sulcus. GEOGRAPHIC RANGE: South America from Colombia, Venezuela, and Ecuador south through B razil to B o livia, Paraguay, Uruguay, and Argentina. HABIT: Leimadophis is arboreal and oviparous. I t feeds on frogs, lizard s, birds, and rodents. GENERIC RELATIONSHIPS: Leimadophis is close to Dromicus, and a llie d Lo Lygophis (although Lygophis has no apical p its and its dorsal scales are not reduced to 15 rows). Xenodon is a larger, shorter ally (Dunn). REFERENCES: Boulenger, 1894; Dunn, 1928b; Fukada, 1964; Hoge, 1957d- Peters, 1960a. LEGEND FOR FIGURE 105: Geographic D istribution of Species of Leimadophis

|ti albiventris it fra s e ri •$:sagitiffer k simonsii ^ .ty p h lu s

LEGEND FOR FIGURE 106: Geographic D istribution of Species of Leimadophis

®/^>melanostigma oligolepis j poecilogyrus

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85* W 75* W 65* W 55* W 45* W 35* W LONG Figure 105.

LONG Figure 106.

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LEGEND FOR FIGURE 107: Geographic Distribution of Species of Leimadophis

// triscalis • zw e ifeli

LEGEND FOR FIGURE 108:

Geographic D istribution of Species of Leimadophis

v irid is

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to

85* W 75* W 65* W Figure 107.

•o n

Figure 108. V^ 1 ------1------1 i I------1— 85* W 75* W 65* W 55* W 45* W 35* W LONG

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GENUS: Leptodeira Fitzinger, 1843 TYPE SPECIES: Coluber annulatus Linnaeus CONTENT: 9 species (see LEGEND)

MORPHOLOGY: Body is cylindrical or moderately compressed with a long or medium- length ta il. Maximum length: 1 meter. Maximum tail length: 20% of body length. Head is distinct from neck. Eye is large with a vertical pupil. SCUTELLATION: Head scutes are normal with the exception of 1-4 preoculars; 6-12 in fra la b ia ls , usually 10; temporals 1+2+3; posterior nasal concave.

17-25 midbody dorsal scale rows. Dorsal scale rows reduced through loss of paravertebrals. Dorsal scales are smooth, with two apical p its . In some the vertebral row is enlarged. 150-211 ventral scutes; ventrals rounded. Anal divided. Keels are rarely present in the anal region. 54-107 caudal scutes; caudals divided. DENTITION: 8-11+II maxillary teeth. Maxillary teeth are subequal in size. Rear fangs are large, grooved. 14-28 mandibular teeth. 7-12 p alatine, and 16-32 pterygoid teeth. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is single, capitate with a simple sulcus. Usually one or more longitudinal rows of enlarged spines are opposite the sulcus. These spines may increase distally in some species. The capitulum may be spinose or crenulate and may have cup-shaped depression. Length: 6-9 caudals. GEOGRAPHIC RANGE: In the Neotropical tropics from southern Sonora, Mexico and the Rio Grande embayment in southern Texas south to Paraguay and northern Argentina. Not in the high Andes or coastal deserts of Peru and Chile. On Aruba, Margarita, Tobago, and Trinidad. 0-1400 m. HABIT: Leptodeira is found in dry environments, although 3 species (L. sept- entrionalis, annulata, and frenata) are found in both wet and dry environments. Leptodeira is found at low to moderate elevations (not over 2000 m.). Leptodeira is arboreal, terrestrial, semiaquatic, and secretive, .as w ell as nocturnal. I t feeds on frogs (including eggs), toads, lizards, and is oviparous. GENERIC RELATIONSHIPS: Leptodeira is closely related to Hypsiglena, Erldiphas, Cryophis, and Tantalophls. The L. punctata group approaches Hypsiglena in general physiognomy. Leptodeira has recently developed arboreal habits (Duellman). Dunn considers Tri- mo rphodon and Hypsiglena to be most closely re la - •" ted to Leptodeira (Scott). REFERENCES: Boulenger, 1896; Duellman, 1958a, 1966a; Duellman and U erler, 1955; Scott, 1969; Tanner, 1966.

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LEGEND FOR FIGURE 109: Distribution of Leptodeira punctata

LEGEND FOR FIGURE 110: Distribution of the Leptodeira nigrofasciata Group

o latifasciata • nigrofasciata

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m

Figure 109.

Figure 110.

too1

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LEGEND FOR FIGURE 111: Distribution of Species of the Leptodeira annulata Group

• frenata x maculata

LEGEND FOR FIGURE 112: Distribution of Species of the Leptodeira annulata Group

* annulata • bakeri

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s Iv

Figure 111,

il0#l«0° 1©0° ¥80° W70° ¥60* ¥50* ¥40* ¥

Figure 112.

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LEGEND FOR FIGURE 113: Distribution of Species of Leptodeira septentrionalis Group

septentrionalis

LEGEND FOR FIGURE 114: D istribution of Species of Leptodeira septentrionalis Group

x splendida

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35 N iue 114. Figure n jt x !C iue 113. Figure 148

GENUS: Lioheterophis Amaral, 1935 TYPE SPECIES: Lioheterophis iherinpi Amaral CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body cylin d rical with a medium-length t a i l . Maximum to ta l length: 360 mm. Maximum tail length: 65 mm. Tail is 1/6 of total length. Head is s lig h tly d istin ct from neck. Eye is medium-sized with a round pupil. SCUTELLATION: Head scutes are normal.

15 dorsal scale rows. Dorsals keeled with no apical pits. 151 ven­ tral scutes; ventrals rounded. Anal divided. 50 caudal scutes; cau­ dals divided. DENTITION: 15-17+2 maxillary teeth. Mandibular teeth subequal-sized. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: No description available. GEOGRAPHIC RANGE: Campina Grande, Estado do Parahyba, B ra zil. Known from type lo c a lity only. HABIT: No information available. GENERIC RELATIONSHIPS: Lioheterophis is sim ilar to Rhadinaea in tooth structure and lack of apical pits. The two genera differ in physiognomy, external chara­ cters, coloration and tail length (Amaral). REFERENCES: Amaral, 1935, 1976. LEGEND FOR FIGURE 115: Geographic Distribution of Lioheterophis iheringi

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50* 40° W

Figure 115.

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GENUS: Liophis Tschudi 1845 TYPE SPECIES: Coluber cobella Linnaeus CONTENT: 23 spceles (see LEGEND)

MORPHOLOGY: Body is c y lin d rical. Maximum length: 730 mm. Maximum t a i l length: 125 mm. Tail is 16-22Z of total length. Head is not distinct from neck. Eye is large, medium, or small. SCUTELLATION: Head scutes are normal except 6-8 supralabials.

17 or 19 dorsal scale rows. Dorsal scales have no apical pits. 143- 170 ventral scutes; ventrals angulate. Anal divided. 45-80+ caudal scutes; caudals divided. DENTITION: 20-24 maxillary teeth. There is no diastema, although the posterior maxillary teeth are slightly enlarged. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is bilobed with a forked sulcus and apical disks. It has basal hooks, but no calyces. GEOGRAPHIC RANGE: South America. HABIT: Liophis is terrestrial, although one species (L miliaris) is aquatic. Liophis feeds on insects (including termites, L. jaegeri), fishes, frogs, toads, lizards, birds, and mammals. Oviparous. GENERIC RELATIONSHIPS: Liophis may be ancestral to Dromicus (Maglio). REFERENCES: Amaral, 1976; Boulenger, 1894; Dixon and Markezich, 1979; Dunn, 1928b; Hoge, 1965; Hoge and Gans, 1965; Maglio, 1970; Peters, 1960a; Roze, 1964. LEGEND FOR FIGURE 116: Geographic Distribution of Species of Liophis fit canaima o longiventris cobella ■*- melanauchen a festae steinbachi # f r e n a t a d subocularis ®ingerhi

LEGEND FOR FIGURE 117: Geographic D istribution of Species of Liophis :«>• amarali //# anomalus ~ b ra z ili breviceps

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Figure 117.

85’ IB' H>5® 165® IB 5® W35® W LONG

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LEGEND FOR FIGURE 118: Geographic Distribution of Species of Liophis

jag eri l jo b e rti

LEGEND FOR FIGURE 119: Geographic D istribution of Species of Liophis

/<$ m ilia ris ’#• obtusus <£>occipitalis VWI purpurans □ taeniurus ■ trebbaui ? albiceps

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Figure 119. 65v TI5# Wo Wo !H5° Wo W LONG

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LEGEND FOR FIGURE 120: Geographic Distribution of Liophis undulatus

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Figure 120.

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GENUS: Lygophis Fitzinger, 1843 TYPE SPECIES: Coluber llnneatus Linnaeus CONTENT: 4 species (see LEGEND)

MORPHOLOGY: Body is cylindrical and slender with a long ta ll. Total length (maximum) is 650 mm. Maximum t a i l length: 190 mm. Head is s lig h tly distinct from neck. The eye is large with a round pupil. SCUTELLATION: Head scutes are normal.

17-19 dorsal scale . Dorsal scales are smooth with no apical pits. 137-178 ventral scutes. Anal divided. 72-94 caudal scutes. Caudals divided. DENTITION: 18-22+11 m axillary teeth. Mandibular teeth are subequal in size. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is bilobed, with a forked sulcus and apical disks. GEOGRAPHIC RANGE: Northern and central Panama to South America. HABIT: Lygophis is arboreal. I t feeds on liza rd s , birds, and rodents. GENERIC RELATIONSHIPS: Lygophis is close to A n tillo p h is. I t may be a compound genus of distantly related forms. The distinctions between Dromicus and Lygophis rest on slim evidence (M aglio). REFERENCES: Amaral, 1976; Boulenger, 1894; Dunn, 1928b; Maglio, 1970; Myers, 1966b, 1973. LEGEND FOR FIGURE 121: Geographic D istrib u tio n of Species of Lygophis

T amoenus %/// flavifrenatus :p; lineatus @ paucidens

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Figure 121.

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GENUS: Lystrophis Cope, 1885 TYPE SPECIES: Heterodon dorbignyi Dumerll, Bibron and Dumeril CONTENT: 3 species (see LEGEND)

MORPHOLOGY: Body Is subcylindrical. Maximum to ta l length: 660 mm. Maximum t a i l length: 80 mm. Head Is not or scarcely d istin ct from neck. Eye is medium-sized with a round pupil. SCUTELLATION: Head scutes are normal with these exceptions: the snout is very short and elevated with an anchor-shaped ro stral which starts at the union of the prefrontal with the frontal and clearly separates the internasals from each other. Suboculars: 0-2.

19-21 dorsal scale rows. Dorsal scales are smooth with apical pits. The first rows are enlarged. 133-173 ventral scutes; ventrals ang- ulate. Anal divided. 25-49 caudal scutes; caudals single. DENTITION: 4-5+2 maxillary teeth. The maxilla is very short. The postdiastemal teeth are large, ungrooved, and three times as long as the other teeth. Mandibular teeth are subequal. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, disked with a forked sulcus and spines. GEOGRAPHIC RANGE: South and southeastern Brazil, Paraguay, Bolivia, northern and cen­ t r a l Argentina and Uruguay. GENERIC RELATIONSHIPS: Lystrophis closely resembles Heterodon. and may not be separable from it. Lystrophis has a similar defense display as Heterodon. (Orej as-Miranda). HABIT: Ms feeds on insects (?), frogs, and lizards. Oviparous.

Amaral, 1976; Boulenger, 1894; Dunn, 1928b; Orejas-Miranda, 1966. LEGEND FOR FIGURE 122: Geographic D istribution of Species of Lystrophis V.* dorbignyi \\ histricus /// semicinctus

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Figure 122.

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GENUS: Manolepis Cope, 1885 TYPE SPECIES: Tomodon nasutus Cope CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body is cylin d rical or la te ra lly compressed with a medium-length t a i l . Maximum length: 550 mm. Maximum t a i l length: 140 mm. Head is distinct from the neck. The eye is large with a vertical pupil. SCUTELLATION: Head scutes are normal.

19 dorsal scale rows. Dorsal scales are smooth with apical pits. 171-186 ventral scutes; ventrals rounded. Anal divided. 69-83 caudal scutes; caudals divided. DENTITION: 15+11 maxillary teeth. The anterior maxillary teeth are longest. The anterior mandibular teeth are also much longer than the post­ erior mandibular teeth. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Ilemipenis is bilobed (Dowling), noncapitate with a forked sulcus, spines and calyces. GEOGRAPHIC RANGE: Western Mexico from Nayarit to Tehuantepec. HABIT: No information available. GENERIC RELATIONSHIPS: Related to Calamodontophis♦ REFERENCES: Boulenger, 1896; Dunn, 1928 b. LEGEND FOR FIGURE 123: Geographic D istribution of Manolepis putnami

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25 N iue 123. Figure 155

GENUS: Nlnia Baird and Girard, 1853 TYPE SPECIES: Ninia diademata Baird and Girard CONTENT: 8 species (see LEGEND)

MORPHOLOGY: Body is c y lin d ric a l with a long or medium-length t a i l . Maximum length: 415 mm. Maximum t a i l length: 125 mm. Head is more or less d is tin c t from the neck. The eye is small with a v e rtic a l or subelliptic pupil. SCUTELLATION: Head scutes are normal with these exceptions: usually no preocular; loreal and prefrontal enter eye; posterior nasal is concave; males have spiny tubercules on chin scutes; supralabials 5-8.

17-21 dorsal scale rows. Reductions of scale rows only occur ab­ normally. Dorsal scales keeled and striated, with no apical pits (Boulenger: apical pits present). Less than 200 ventral scutes; ventrals rounded. Anal single. 37-101 caudal scutes; caudals divided. DENTITION: 15-18 maxillary teeth. Maxillary teeth small, subequal in size. Mandibular teeth subequal in size. VERTEBRAE: Hypapophyses present on posterior vertebrae. Neural spine is en­ larged and has lateral expansions. Zygapophyses slightly enlarged. HEMIPENIS: Hemipenis is single (Dowling), capitate, with a forked sulcus. It has proximal hooks and calyces. The areas so furnished are equal in length. GEOGRAPHIC RANGE: Trinidad, Venezuela, Colombia, and Ecuador north through Central America to southern Oaxaca on the P acific and to Hidalgo on the Atlantic coast. 0-1830 m. HABIT: Ninia is a member of the humid montane herpetofaunal assemblage (Duellman). Terrestrial, crepuscular, secretive, Ninia feeds on slugs, worms, caecilans and beetles (?)(Scott). GENERIC RELATIONSHIPS: Ninia occupies a central position between a group of burrowing and a group of arboreal forms (Dunn). Chersodromus and Diaphorolepis seem to resemble N in ia, except for fused prefrontals. Ninia is the least modified member of the group including Geophis-At ractus-Carphophis-Farancia. Ninia occupies a central position in re latio n to Tropidodlpsas-Sibon-Sibynomorphus (Peters). The resemblance between Ninia and Diaphorolepis is rbe result of parallel evolution (Bogert). REFERENCES: Bogert, 1964; Boulenger, 1893; Duellman, 1966b; Dunn, 1928b, 1935; Peters, 1960a; Scott, 1969; Stuart, 1950.950.

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LEGEND FOR FIGURE 124: Geographic Distribution of Species of Ninia

atrata + cerroensis hudsoni

LEGEND FOR FIGURE 125: Geographic D istribution of Ninia diademata

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Figure 124.

110* w 100* V 90* V Figure 125.

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LEGEND FOR FIGURE 126: Geographic Distribution of Ninia sebae

LEGEND FOR FIGURE 127: Geographic D istribution of Species of Ninia

k/l maculata aE*’ oxynota •.£>.. psephota

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-1 15 N 2 ------105 TV 105 : iue 126. Figure o 85° W iue 127 Figure 158 GENUS: Nothopsls Cope, 1871 TYPE SPECIES: Nothopsls rugosus Cope CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body Is slender, compressed with a long t a ll. Maximum length: 433 mm. T a il Is 40-45% of head to body length. Head Is d istin ct from neck. Eye Is small, placed dorsally, with a round pupil. SCUTELLATION: Head scales are reduced and invaded by small scales. Most of the usual colubrid scutes are broken up to some degree. Prefrontals in some are broken up into 3-5 rows of small, keeled scales (SO­ SO). Frontals usually divided; parietals separated by 1-3 rows of small, keeled scales (30-60). Loreal area occupied by 5-10 smooth scales that are larger than the dorsal. Eye is surrounded by a ring of 16 scales, some of which are enlarged. Two rows of scales between eye and supralabials. Temporal region has 7-10 rows of scales, similar to dorsals. 11 supralabials; 13 infralabials.

24-30 dorsal scale rows. Reduction of dorsal rows through loss of 7th row. Dorsal scales are heavily keeled with no apical pits. 149-162 ventral scutes; the sides of the ventrals are angulate. The anal is single. 81-112 caudal scutes; caudals divided. DENTITION: 17-21+2 maxillary teeth. The anterior maxillary teeth are longest. 31-32 mandibular teeth. 10-11 palatine, and 27 pterygoid teeth. VERTEBRAE: Hypapophyses present on posterior vertebrae. Neural spine is en­ larged. Zygapophyses are enlarged. HEMIPENIS: Hemipenis is single with a forked sulcus. Spines are situated near the bifurcation of sulcus. The basal h alf is covered with tiny spinules near the sulcus. These join to form small papillate caly­ ces that extend along and between the sulci to the tip of the organ. Large spines are proximal to the fork and extend d is ta lly as paired series of smaller spines along the outer edge of each lobe. Length: extends to 6 th caudal. GEOGRAPHIC RANGE: San Juan River, Nicaragua south to Costa Rica, Panama, and choco of Colombia to Salidero, Ecuador. HABIT: Found in damp forest from 100 to 3000 meters. Terrestrial. Nocturnal. One stomach contained L 0*. a salamander (S co tt). sk GENERIC RELATIONSHIPS: 1 The hemipenis of Nothopsis resembles that of Synophis V and Diaphorolepis. Nothopsis is a distinct genus with no apparent close relationships (Dunn and Dowling). May be a relic of an ancient line of colubrids that ^ antedates the ancestors of the majority of modern mmctum ] r forms in the Americas (S c o tt). I J REFERENCES: 1 / Bogert, 1964; Boulenger, 1893; Dunn, 1940; Dunn and Dowling, ^ 1957; Scott, 1969. LEGEND FOR FIGURE 128: Geographic D istribution of Nothopsis rugosus

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Figure 128.

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GENUS: Oxyrhopus Wagler, 1830 TYPE SPECIES: Oxyrhopus petola Linnaeus CONTENT: 12 species (see LEGEND)

MORPHOLOGY: Body cylindrical or feebly compressed. Tail long or medium-length. Maximum length: 980 mm. Maximum t a i l length: 190 mm. Head is distinct from neck. Eye is medium or small with a vertical pupil. SCUTELLATION: Head scutes are normal.

15-19 dorsal scale rows. Dorsal scales are smooth with 0-2 apical pits. 172-236 ventral scutes; ventrals rounded or angulate. Anal single, or divided. 47-126 caudal scutes; caudals single or divided. DENTITION: 10-15+11 m axillary teeth, subequal in size. Fangs are modestly en­ larged. Anterior mandibular teeth are largest. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, bicapitate, with a forked sulcus. Calyces are present distally, spines present proximally. A smooth area at each apex. GEOGRAPHIC RANGE: Southern Mexico to about 35°S la titu d e east of the Andes and to ju st north of Lima, Peru. East of the Andes in South America to B razil and Argentina. 0-700 ri. HABIT: Terrestrial. Nocturnal. Oxyrhopus feeds on lizards as juveniles and on mammals as adults. Oviparous. GENERIC RELATIONSHIPS: Included in the Pseudoboini by Bailey. REFERENCES: Bailey, 1967; Boulenger, 1896. LEGEND FOR FIGURE 129: Geographic D istribution of Species of Oxyrhopus

x b a ileyi o clathratus ui doliatus fitz in g e ri <$■ petola LEGEND FOR FIGURE 130: Geographic D istribution of Species of Oxyrhopus

• marcapatae // melanogenys

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LAT 129. Figure 85 W 75 W 75 W 85 C i V i IC liOb«B *D# ID * 10* W0# Tf0° 10° W W0# 10° Tf0° 10* * ID *D# liOb«B L j \ ' ( ''-' (S N LONG LONG 55 W 55 iue 130. Figure 160

LEGEND FOR FIGURE 131: Geographic Distribution of Species of Oxyrhopus

// formosus * = leucomelas ^ rh o m b ife r trigenimus • venezuelanus

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Figure 131.

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GENUS: Parapostolepis Amaral 1930 TYPE SPECIES: Apostolepis polylepis CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Total body length: 620 mm. Maximum t a i l length: 33 mm. Eye tiny. SCUTELLATION: Large, angulate rostral, conical snout; internasals fused to pre- frontals; 0 temporals; 1 pre- and 1 postocular; preocular tiny; 6 supralabials.

17 dorsal scale rows. Dorsals smooth with no apical pits. 214- 236 ventral scutes. Anal divided. 20-26 caudal scutes; caudals divided. DENTITION: No information available. VERTEBRAE: No information available. HEMIPENIS: No information available. GEOGRAPHIC RANGE: Known only from type lo c a lity : Eng. Dodt, Municipio de Santa Filomena, Estado do Piaui, B ra zil. HABIT: No information available. GENERIC RELATIONSHIPS: No information available. REFERENCES: Amaral, 1921, 1930. LEGEND FOR FIGURE 132: Geographic D istribution of Parapostolepis polylepis

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Figure 132.

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GENUS: Paraptychophis Lema, 1967 TYPE SPECIES: Paraptychophis meyeri Lema CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body cylindrical with a medium-length, specialized (pointed) ta il. Total length: 594 mm. Maximum t a il length: 154 mm. Head d istin ct from neck. Eye medium-sized with a round pupil. SCUTELLATION: Head scutes normal.

17 dorsal scale rows. Dorsal scales keeled with 2 apical pits. 123 ventral scutes; ventrals rounded. Anal divided. 59 caudal scutes; caudals divided. DENTITION: 15+11 maxillary teeth. 23 mandibular teeth. 12 palatine teeth. 19-20 pterygoid teeth. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: No description available. GEOGRAPHIC RANGE: Known only from type lo c a lity : Porto Alegre, Estado do Rio Grande do Sul, B razil. HABIT: No information available. GENERIC RELATIONSHIPS: Sim ilar to Helicops in morphology (Lema) REFERENCES: Lema, 1967. LEGEND FOR FIGURE 133: Geographic D istribution of Paraptychophis meyeri

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iue 133. Figure LAT 80 ¥ 70 60 ¥ 60 70 ¥ 80 LONG

50 ¥ 50 40 ¥ 40 163

GENUS: Phllodryas Wagler, 1830 TYPE SPECIES: Coluber Olfersll Lichtenstein CONTENT: 13 species (see LEGEND)

MORPHOLOGY: Body Is cylindrical or slightly compressed with a long ta il. Max­ imum length: 1050 mm. Maximum t a il length: 310 mm. Head is d istin c t from the neck with a d istin ct canthus ro s tra lis . The eye is large or medium-sized with a round pupil. SCUTELLATION: The head scutes are normal with these exceptions: the loreal may be present or absent; V_. oligolepis has 4 internasals.

15 or 17 dorsal scale rows. Dorsal scales smooth or keeled. Dorsal rows oblique. Dorsals with 1 or 2 apical pits. 157-231 ventral scutes; ventrals rounded or laterally angulate. Anal divided. 82- 140 caudal scutes; caudals divided. DENTITION: 12-15+11 m axillary teeth. Prediastemal teeth subequal in size. Fangs large, grooved. Anterior mandibular teeth are longest. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, semicapitate (Dowling) or noncapitate. It is spinose proximally and calyculate distally. The forked sulcus is centrifugal. The sulcus is deeply forked with lateral spines. Calyces present on apex of each lobe. GEOGRAPHIC RANGE: South America. HABIT: Philodryas is arboreal, diurnal, and oviparous. It feeds on frogs, lizards, snakes, and birds. GENERIC RELATIONSHIPS: Philodryas and Conophis may be related (Maglio). The difference between Philodryas and Conophis is the presence of 1 apical p it in Philodryas and none in Conophis (Boulenger). REFERENCES: Amaral, 1921, 1976; Boulenger, 1896; Dowling, 1969; Lema, 1962; Maglio, 1970; Peters, 1970; Thomas, 1975, 1977a; 1977b. LEGEND FOR FIGURE 1341 Geographic D istribution of Species of Philodryas

^/carbonelli

viridissimus

LEGEND FOR FIGURE 135: Geographic D istribution of Species of Philodryas

® elegans o lfe rs i

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m • ! • V * •• ;

Figure 135.

82 ’ LONG

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LEGEND FOR FIGURE 136: Geographic Distribution of Species of Philodryas

| \ psammophideus oligolepis _‘I natereri

LEGEND FOR FIGURE 137: Geographic D istribution of Species of Philodryas

= - aestivus :jk] arnaldoi <§> baroni ® bunneisteri •:imattogrossensis

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LAT 136. Figure 8°7# 65° 55° 45° 35°W n85°W75#W V W W \ D < *80° W70* 60° 50°W W If40° W ------i LONG LONG ------I ------1 ------iue 137. Figure 165

GENUS: Phimophls Cope, 1860 TYPE SPECIES: Rhinosimus Guerini Dumeril, Blbron, and Dumeril CONTENT: 4 species (see LEGEND)

MORPHOLOGY: Body is cylin d rical or feebly compressed with a long or medium- length t a l l . Maximum length: 1120 mm. Maximum t a il length: 250 mm. Head is distinct from neck. Eye is small with a vertical pupil. SCUTELLATION: Head scutes are normal with the exception that the rostral is sharp­ ly pointed and curved back and that P_. ig le s ia s i has no lo real.

17-19 dorsal scale rows. Dorsal scales smooth with 2 apical pits. 185-211 ventral scutes. Anal single 70-99 caudal scutes; caudals divided, or variable. DENTITION: 11+11 m axillary teeth. M axillary teeth subequal in size. Anterior mandibular teeth are longest. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, bicapitate, with a forked sulcus. Spines, calyces, and medial apical awns are present. GEOGRAPHIC RANGE: From Panama to central Argentina in grassland regions. HABIT: Phimophls is arboreal, diurnal, and oviparous. It feeds on lizards and other vertebrates. Omnicarnivorous. GENERIC RELATIONSHIPS: Phimophls is a member of Bailey's Pseudoboini. REFERENCES: Amaral, 1976; Bailey, 1967; Boulenger, 1896. LEGEND FOR FIGURE 138: Geographic Distribution of Species of Phimophis

^ g u e r in i ig le s ia s i :$■ vittatus LEGEND FOR FIGURE 139: Geographic D istribution of Phimophls guianensis

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CM Figure 139 85 W 75 W 65 W 55 W

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GENUS: Platynion Amaral, 1923 TYPE SPECIES: Platynion lividium Amaral CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body is cylindrical with a medium-length ta il. Maximum length: 730 mm. Maximum t a il length: 165 mm. Neck is broad and head is not d istin ct from neck. Eye is medium-sized with a round pupil. SCUTELLATION: Head scutes are normal.

17 dorsal scale rows. Dorsal scales smooth with one apical pit. 162-212 ventral scale rows. Ventrals rounded. Anal divided. 71 caudal scutes; caudals divided. DENTITION: 5+1 maxillary teeth. Maxillary teeth subequal in size. Single fang is large. Anterior mandibular teeth are longest. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses not enlarged. HEMIPENIS: No information available. GEOGRAPHIC RANGE: Matto Grosso, Parana, and Sao Paulo, B razil. HABITS: No information abailable. GENERIC RELATIONSHIPS: No information available. REFERENCES: Amaral, 1923. LEGEND FOR FIGURE 140: Geographic D istribution of Platynion lividum

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iue 140. Figure LAT 5 7 W 75 W 85 LONG 5 W 35 167

GENUS: Pllocercus Cope, 1860 TYPE SPECIES: Pllocercus elapoldes Cope CONTENT: 8 species

MORPHOLOGY: Body is cylindrical with a long ta il. Maximum length: 560 mm. Maximum ta il length: 260 mm. Tail is 2/5 total body length. Head is not or scarcely d is tin c t from neck. Eye is medium-sized or small with a round pupil. SCUTELLATION: Head scutes are normal.

17 dorsal scale rows. Dorsal scales smooth with no pits. 120-143 ventral scutes; ventrals rounded. Anal divided. 85-127 caudal scutes; caudals divided. DENTITION: 18+2 maxillary teeth. Rear maxillary teeth enlarged, but not groov­ ed. Mandibular teeth subequal in size. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is bilobed, capitate with a forked sulcus. I t has spines and calyces. GEOGRAPHIC RANGE: Southern Tamaulipas and the Isthmus of Tehuantepec southward on both coasts into South America. 0-1680 m. HABIT: Terrestrial. Nocturnal. Stomach of one contained species of sal­ amanders. Eats frogs in captivity (Scott). GENERIC RELATIONSHIPS: The length of Pllocercus* ta il separates it from Erythrolamprus (Cope). Pllocercus is related to Rhadinaea and Coniophanes (S co tt). REFERENCES: Boulenger, 1894; Cope, 1860; Peters, 1960a; Scott, 1967; Smith, 1942a; Smith and Landry, 1965. LEGEND FOR FIGURE 141: Geographic D istribution of Species of Pllocercus

/•/euryzonus

LEGEND FOR FIGURE 142: Geographic D istribution of Species of Pllocercus //j andrewsi bicolor elapoldes

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:2 ; o

o

cc o 85° V 75* W 65* W

Figure 141.

Z

Figure 142.

I IC fu J loc^uj 9CfuJ tfu?

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LEGEND FOR FIGURE 143: Geographic D istribution of Species of Pllocercus aequalis • annellatus dimidiatus TT arubricus

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LAT iue 143. Figure 85 W 85 75 W 75 169

GENUS: Pseudablabes Boulenger, 1896 TYPE SPECIES: Eiremis agassizii Jan CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body cylindrical with a medium-length ta il. Maximum length: 380 mm. Maximum t a il length: 85 mm. Head scarcely d istin ct from neck. Eye medium-sized with a round pupil. SCUTELLATION: Head scutes normal.

15+13+13 dorsal scale rows. Dorsal scales are smooth with apical p its . 128-138 ventral scutes; ventrals are rounded. Anal divided. 51-64 caudal scutes; caudals divided. DENTITION: 14+11 maxillary teeth. Prediastemal teeth are small, equal in size. Fangs are enlarged. Mandibular teeth are subequal-sized. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is bilobed, noncapitate with a forked sulcus and calyces. GEOGRAPHIC RANGE: South and southwestern B ra z il, central and northeastern Argentina, and Uruguay. HABIT: No information available. GENERIC RELATIONSHIPS: No information available. REFERENCES: Boulenger, 1894, 1896; Dunn, 1928 b. LEGEND FOR FIGURE 144: Geographic D istribution of Pseudablabes agassizi

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. LONG Figure 144.

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GENUS: Pseudoboa Schneider, 1801 TYPE SPECIES: Pseudoboa coronata Schneider CONTENT: 4 species (see LEGEND)

MORPHOLOGY: Body is cylin d rical or feebly compressed with a medium-length t a il. Maximum length: 1180 mm. Maximum t a i l length: 240 mm. Head is distinct from neck. Eye is small or tiny with a vertical pupil. SCUTELLATION: Head scutes are normal.

17 or 19 dorsal scale rows. Dorsal scales smooth with 2 apical pits. 171-208 ventral scutes; ventrals rounded or angulate. Anal single. 64-97 caudal scutes; caudals single. DENTITION: 10-15 +11 maxillary teeth. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, b icap itate, with a forked sulcus and d istal bands of spines. Calyces are present on each lobe. GEOGRAPHIC RANGE: South America east of the Andes to Santa Catarina, B ra zil, and cen­ tr a l B olivia; west of the Andes in Colombia, and in western Panama, Tobago, and Grenada Islands. HABIT: Pseudoboa is terrestrial, nocturnal, and oviparous. Juveniles feed on lizards and adults feed on mammals. GENERIC RELATIONSHIPS: Pseudoboa is a member of B ailey’ s Pseudoboini. REFERENCES: Amaral, 1976; Bailey, 1967; Boulenger, 1896; Dunn, 1928 LEGEND FOR FIGURE 145: Geographic D istribution of Species of Pseudoboa

— coronata /1 haasi //^newiedii /*n ig ra

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Figure 145.

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GENUS: Pseudoeryx Fitzinger, 1826 TYPE SPECIES: Coluber pllcatills Linnaeus CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body Is cylindrical and stout with a short ta ll. The tall termina­ tes In a hard, blunt spine. Maximum length: 1070 mm. Maximum tall length: 127 mm. Head Is not distinct from neck. Eye is small with a round pupil. SCUTELLATION: Head scutes are normal with these exceptions: no preocular; no loreals (fide Roze); one internasal (internasals fused); nasals in contact; nostril directed upward In a semi-divided nasal.

15 dorsal scale rows. Dorsal scales smooth with no apical pits. 129-163 ventral scutes; ventrals rounded. Anal divided. 32-51 caudal scutes; caudals divided. DENTITION: 15-17 maxillary teeth. Maxillary teeth increase in length poster­ iorly. 12-18 mandibular teeth. Anterior mandibular teeth a little smaller than posterior teeth. 8 palatine, and 18-19 pterygoid teeth. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, b icap itate, with a forked sulcus. I t is spinose proximally, followed by a zone of papillate flounces. These grade into a well-developed calyculate region on the apex of each lobe. Spines are a ll small and hooked, with no enlarged spines. Sulcus forks near the base of the organ. Length: 14 subcaudals. GEOGRAPHIC RANGE: Colombia and Guyanas to B o livia, Paraguay, and northern Argentina. Widespread Amazonian d istrib u tio n (Dixon). HABIT: Aquatic, especially found in water hyacinths and other massed vegetation. Feeds on fishes and frogs. GENERIC RELATIONSHIPS: Pseudoeryx is related to Farancia, and gave rise to Hydrops and Helicops (Neill) It is unlikely that Pseudoeryx is closely related to H elicops or Hydrops (Rossman). REFERENCES: Boulenger, 1894; Dixon, 1978; Hoge, 1964a; N e ill, 1964; Peters, 1960a; Rossman, 1973b; Roxe, 1957; W illiam s, 1968. LEGEND FOR FIGURE 146: Geographic D istribution of Pseudoeryx p lic a tilis

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n

85 H> 165 TB5 H45 1B5 W LONG

Figure 146.

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GENUS: Pseudotomodon Koslowsky, 1896 TYPE SPECIES: Pseudotomodon mendozinus Koslowsky CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body is cylindrical with a short tail. Head distinct from neck. Eye is medium-sized with a subround pupil. SCUTELLATION: Head scutes are normal.

17 dorsal scale rows. Dorsal scales smooth or keeled in oblique rows. 1 apical p it. 153 ventral scutes; ventrals rounded. Anal divided. 41 caudal scutes; caudals divided. DENTITION: 8+2 maxillary teeth. Postdiastemal teeth are huge. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is 7 subcaudals long and bilobed. Sulcus forks at sub- caudal 4. Lobes begin at subcaudal 5. Spinose from subcaudal 1 to lobes. Spines connected by inconspicuous membranes to tip of lobe. No obvious capitation. No well developed calyces (Dowling and Jenner). GEOGRAPHIC RANGE: Western Argentina from Catamarca to Chubut. HABIT: Pseudotomodon may be viviparous. GENERIC RELATIONSHIPS: Pseudotomodon is related to Tomodon, Thamnodynastes, Tachymenis, Gomesophis, Calamodontophis (B ailey). Pseudotomodon is quite similar to Tomodon and Philodryas (Peracca). REFERENCES: B ailey, 1966; Peracca, 1897. LEGEND FOR FIGURE 147: Geographic D istribution of Pseudotomodon trigonatus

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Figure 147.

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GENUS: Ptychophis Gomes, 1915 TYPE SPECIES: Ptychophis flavovirgatus Gomes CONTENT: 1 species

MORPHOLOGY: Pupil round. No further information. SCUTELLATION: 132 ventral scutes. 61 caudal scutes; caudals divided.

Head scutes normal. DENTITION: 18+11 maxillary teeth. Fangs enlarged. VERTEBRAE: No information. HEMIPENIS: Hemipenis is bilobed, almost single, with a forked sulcus. Spinose to apex, spines are smaller on the apex. Noncapitate. GEOGRAPHIC RANGE: Santa Catharina and Parana, B razil. HABIT: Ptychophis bears liv e young. GENERIC RELATIONSHIPS: Ptychophis is related to Tomodon, Pseudotomodon, Calamodontophis, Gome^ophis, Thamnodynastes, and Tachymenis (B ailey). REFERENCES: Bailey, 1966. LEGEND FOR FIGURE 148: Geographic D istribution of Ptychophis flavovirgatus

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iue 148. Figure LAT —>/ •— LONG 5 3 W 35 W 45 174

GENUS: Rhachidelus Boulenger, 1908 TYPE SPECIES: Rhachidelus brazil! Boulenger CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Maximum length: 1320 mm. Maximum t a i l length: 310 mm. Head is flattened, moderately distinct from neck. Eye large to medium with a vertical pupil. SCUTELLATION: Head scutes are normal with the exception of the loreal fused to the posterior nasal and 3+4 temporals.

25-29 dorsal scale rows. Dorsal scales smooth with 2 apical pits. Vertebral row enlarged: nearly as long as broad. 184 ventral scutes. Anal single. 80 caudal scale rows; last 28 caudals paired, remainder single. DENTITION: 15+11 maxillary teeth. Prediastemal teeth increase slightly in size posteriorly. Fangs 1 3/4 the size of the prediastemal teeth. Last fang is offset (Dowling and Jenner). VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is long (18 subcaudals) and bicap itate. Base is nude with tin y spinules (to subcaudal 7) where 8 rows of large spines extend to forking of organ. Spines around base and between lobes. At subcaudal 12 the lobes diverge. Lobes have d is tin c t capitate areas of uniform, small calyces that extend to the tip of each lobe. The sulcus forks at subcaudal 7 (Dowling and Jenner). GEOGRAPHIC RANGE: Southern B razil and Missiones, Argentina. HABIT: Rhachidelus is te rre s tria l and diurnal. I t is omnicarnivorous and also eats birds. It is oviparous. GENERIC RELATIONSHIPS: Rhachidelus is one of Bailey's Pseudoboini. It is allied to Clelia or to Oxyrhopus.

REFERENCES: Amaral, 1976; Bailey, 1967, 1966; Boulenger, 1908. LEGEND FOR FIGURE 149: Geographic D istribution of Rhachidelus b r a z ili & A

I

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Figure 149.

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GENUS: Rhadinaea Cope, 1863 TYPE SPECIES: Taeniophls vermiculatlceps Cope CONTENT: 44 species (see LEGEND)

MORPHOLOGY: Body is cylindrical with a specialized, medium-length ta il. The ta il terminates in a conical, slender spine. Maximum length: 900 mm. Maximum t a i l length: 14-48% of to ta l length. Head is s lig h tly d is tin c t from the neck. The eye is usually medium-sized, but may be small or large with a round pupil. SCUTELLATION: Head scutes are normal except for 1-3 preoculars.

15-21 dorsal scale rows. No reductions in most species. Dorsal scales are smooth with no apical pits. 110-197 ventral scutes; ventrals rounded or angulate. Anal divided; anal ridges may be present. 31-137 caudal scutes; caudals divided. DENTITION: 1CH-2 to 24+2 maxillary teeth. Postdiastemal teeth are enlarged, and rarely grooved. Mandibular teeth are subequal. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is s lig h tly bilobed or single, capitate, with a forked sulcus. It is short and spinose proximally with a capitate tip. Distal calyces are present. The usual shape is slightly bilobed or single. Lobes are entirely calyculate and contained in a single capitulum. The midportion of the organ is spinose. The base is nude with spinules. There is a trend in Rhadinaea toward loss of bilobation (Myers). GEOGRAPHIC RANGE: American mainland between 35°N la titu d e (Cape H atteras), to 35° S latitude (east-central Argentina). 0-3200 m. HABITS: Rhadinaea is found in humid forested regions: pine, oak woodlands and cloud forests of Mexico and upper Central America; humid tropical broadleaf forests, including montane and lowland rainforests. Rhadinaea is te rre s tria l or semifossorial and diurnal. Diet in c l­ udes insects (pupae also ), frogs (including eggs), salamanders, lizards, snakes (including eggs). REFERENCESz B ailey, 1937, 1940; Boulenger, 1894; Dunn, 1928b 1938a; Myers, 1967, 1973, 1974; N e ill, 1954; Rossman, 1965.

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LEGEND FOR FIGURE 150: Geographic Distribution of Rhadinaea flavilata

LEGEND FOR FIGURE 151: Geographic D istribution of Rhadinaea laureata

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15 N cu iue 150. Figure iue 151. Figure 100° w 100° LEGEND FOR FIGURE 152: Geographic D istribution of the Rhadinaea decorata Species Group :$■: decorata

LEGEND FOR FIGURE 153: Geographic D istribution of the Rhadinaea decorata Species Group a bogertorum x cunneata o forbesi ♦ gaigeae • hesperia A macdougalli * marcellae □ montana a myersi 9 quinquelineata

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Figure 152.

I«0‘ lo c f

Figure 153.

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LEGEND FOR FIGURE 154: Geographic D istribution of Rhadinaea taeniata Species Group • fulvittus o omiltemana $: taeniata

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Figure 154.

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LEGEND FOR FIGURE 155: Geographic D istribution of the Rhadinaea godmani Species Group • lachrymans omontecristi a pilonaorum ®pinicola o serperaster gposadasi

LEGEND FOR FIGURE 156: Geographic D istribution of the Rhadinaea godmani Species Group o hempsteadae • godmani o kinkelini aschistosa •thannsteini

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LAT 155. Figure m«3 2 2 *” 1 8 9

95 o 5 75* W 85* W ' W 88 ° * ° 78° V iue 156. Figure 180

LEGEND FOR FIGURE 157: Geographic D istribution of the Rhadinaea callig aste r Species Group • calligaster

LEGEND FOR FIGURE 158: Geographic D istribution of the Rhadinaea vermiculaticeps Species Group &pulveriventris • vermiculaticeps a sargenti

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iue 157. Figure 15 N O 05° W 05° 75° W 75° iue 158 Figure 181

LEGEND FOR FIGURE 159: Geographic D istribution of the Rhadinaea la te ris trig a Species Group % decipiens a dumerilii • fulviceps o guentheri Alateristriga □ multilineata ■ pachyura

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Figure 159.

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LEGEND FOR FIGURE 160: Geographic D istribution of the Rhadinaea b reviro stris Species Group • a ffin is x bilineata V: persim ilis

LEGEND FOR FIGURE 161: Geographic D istribution of the Rhadinaea breviro stris Species Group • occipitalis o poecilopogon a brevirostris

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I, AT iue 160, Figure C V > ° v.' 75° 75° v.'CV ° > Vi LONG LONG 53° Vi iue 161, Figure 183

GENUS: Saphenophis Myers, 1973 TYPE SPECIES: Dromlcus boursieri Jan and Sordelli, 1867 CONTENT: 5 species (see LEGEND)

MORPHOLOGY: Maximum length: 540 mm. Maximum t a il length: 115 mm. Ratio of t a il to to ta l length: 0.217. Head is a l i t t l e wider than the neck. Eye is medium-sized with a round pupil. SCUTELLATION: Head scutes are normal with the exception of the following: nasal is essentially single; loreal fused with the preocular; preocular is large and single; 2 postoculars; fusion of ocular-loreal region is not uncommon.

15-19 dorsal scale rows. Dorsal scales smooth, no apical pits. Reduction of dorsal scale rows through loss of 4th row. 146-174 ventral scutes. Anal divided. 51-87 caudal scutes; caudals divided. DENTITION: 19-22+2 m axillary teeth. Prediastemal teeth Subequal. Postdia- stemal teeth two times as long, not grooved. 24-26 mandibular teeth. 11-14 palatine, and 24-26 pterygoid teeth. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, bicapitate with a forked sulcus. The organ is bifurcate for 30-50% of its length. The partly calyculate lobes are not contained in a single capitulum. The areas of calyces are separated and not confluent at the bases. The lobes are nude on the asulcate side and calyculate on the sulcate side. The sulcus is deeply forked. Spines are also present. GEOGRAPHIC RANGE: Panama to the Andes of Ecuador and Colombia and the adjoining Amazonian lowlands of Ecuador and Peru. To 3200 m. HABIT: No information. GENERIC RELATIONSHIPS: No information. REFERENCES: Myers, 1966b, 1969a, 1969b, 1973. LEGEND FOR FIGURE 162: Geographic D istrib u tio n of Species of Saphenophis cantioquensis atahuallpae .&• boursieri & sneiderni |^| tristriatus

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Figure 162.

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GENUS: Scolecophis Fitzinger, 1843 TYPE SPECIES: Calamaria atrocincta Schlegel CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body is cylindrical with a short ta il. Maximum length: 370 mm. Maximum t a i l length: 47 mm. Head is s lig h tly d istin ct from neck. Eye is small with a round pupil. SCUTELLATION: Head scutes are normal.

15 dorsal scale rows. Dorsal scales are smooth, or feebly keeled with no apical pits. 181-198 ventral scutes; ventrals are angulate. Anal single. 45-54 caudal scutes; caudals divided. DENTITION: 13-15+11 m axillary teeth. Prediastemal teeth are subequal in size. Postdiastemal teeth are feebly enlarged and grooved. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is short, extends to subcaudal 7. Nude proximally with a band of large spines beginning at subcaudal 3 on side opposite sulcus with enormous single spine proximally, followed by about four rows of large spines which diminish in size d is ta lly . Apex of organ with large spinulose calyces which extend to end. Sulcus apparently unforked, organ is single (Dowling and Jenner). GEOGRAPHIC RANGE: Moderate elevations and dry uplands along the P acific slope from El Salvador to Costa Rica. 400-1230 m. HABIT: Fossorial. Stomach of 1 specimen contained a large centipede (Dowling and Jenner). GENERIC RELATIONSHIPS: Dunn and Bailey believed Scolecophis to be related to Tantilla annulata (Scott). REFERENCES: Boulenger, 1896; Cope, 1886; Scott, 1969. LEGEND FOR FIGURE 163: Geographic D istribution of Scolecophis atrocinctus

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Figure 163.

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GENUS: Sibon Fitzinger, 1826 TYPE SPECIES: Coluber nebulatus Linnaeus CONTENT: 9 species (see LEGEND)

MORPHOLOGY: Body Is compressed laterally, with a long, slim ta ll. Head Is dis­ tinct from neck. Eye is large with a vertical pupil. SCUTELLATION: Head scutes normal with the following exceptions: la b ia l beneath primary temporal greatly enlarged and in contact with postocular, primary, and secondary temporal.

13 or 15 dorsal scale rows. No reductions in scale rows. Dorsal scales are smooth with no apical pits. 136-201 ventral scutes; ven- trals are occasionally divided. Anal single. 41-126 caudal scutes; caudals divided. DENTITION: 15 maxillary teeth. Anterior teeth are longest; remainder are sub­ equal in size. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, capitate with a forked sulcus. The tip is slightly bilobed, but not divided. The proximal portion is spinose. The spines are slightly recurved. There are several enlarged basal spines. The distal portion is calyculate with fairly long papillae. There is a constriction at the border between the spinose and caly­ culate parts, giving a prominent capitate appearance. GEOGRAPHIC RANGE: Mexico from Michoacan on the west and Veracruz on the east, excluding the highlands; south to northern South America, including equatorial B ra zil, and Ecuador. In Trinidad and Tobago. 0-1500 m. HABITS: Sibon is arboreal and nocturnal. It feeds on snails and slugs. GENERIC RELATIONSHIPS: Sibon has developed most of the modifications necessary fo r arboreal existence (Peters). Sibon is a member of Peters' subfamily Dipsadinae, which includes Dipsas, Sibynomorphus. Tropidodipsas is perhaps most closely related to Sibon (ScottV REFERENCES: Henderson, Hoevers, and Wilson, 1977; Hidalgo, 1979 Peters, 1957a, 1960c; Scott, 1969. LEGEND FOR FIGURE 164: Geographic D istribution of Species of Sibon \> c a rri dunni • nebulata

LEGEND FOR FIGURE 165: Geographic D istribution of Species of Sibon j^annulata HI anthracops iW'dimidiata ^ s a n n io la

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Figure 164.

Figure 165.

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LEGEND FOR FIGURE 166: Geographic D istribuiton of Species of Sibon • argus olongifrenis

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure 166.

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GENUS: Sibynomorphus Fitzinger, 1843 TYPE SPECIES: Sibynomorphus mlkanii Schlegel CONTENT: 6 species

MORPHOLOGY: Body is cylindrical, or only slightly laterally compressed with a short t a il. The head is d istin ct from the neck. The eye is medium­ sized. SCUTELLATION: The head scutes are normal.

15 dorsal scale rows. Dorsal scale rows are reduced through loss of paravertebrals. The dorsal scales are smooth with no apical pits. The vertebral row may be slightly or not enlarged. There are usu­ a lly less than 175 ventral scutes; ventrals rounded. Anal single. 37 to 85 caudal scutes; caudals divided. DENTITION: The anterior maxillary is edentate. Maxillary teeth have the tooth edge directed inwards. The mandibular teeth increase in size post­ e rio rly . VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: The hemipenis is single, capitate with a forked sulcus. I t is short. Apex undivided. The proximal portion has hooks and spines; the dis­ tal portion is calyculate; a collar at the border between the spin­ ose and calyculate portions is weakly defined or absent. GEOGRAPHIC RANGE: Southern h a lf of B ra zil, Amazonian Peru, eastern B olivia, Uruguay, Paraguay, and northern Argentina. HABIT: Sibynomorphus is arboreal and nocturnal. It feeds on snails and slugs. GENERIC RELATIONSHIPS: Sibynomorphus has monophagous adaptations for eating snails and slugs, but retains the cylindrical body and non- or slightly enlarged vertebral scale row typical of nonarboreal snakes (Peters). REFERENCES: Peters, 1960c; Rossman and Thomas, 1979. LEGEND FOR FIGURE 167: Geographic D istribution of Species of Sibynomorphus \||ty mikanii a o n e illi + turgidus • vagrans o vagus .ofc; ventrimaculatus

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^ - i ------>------,L^_ 80’ 170* 1 60° W 50° 1 40° V LONG

Figure 167.

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GENUS: Slmophis Peters, 1860 TYPE SPECIES: Heterodon rhinostoma Schlegel CONTENT: 2 species (see LEGEND)

MORPHOLOGY: Body is cylindrical and elongate with a medium-length t a il . Max­ imum length: 730 mm. Maximum t a il length: 140 mm. Head is s lig h tly d istinct from neck. Eye is medium-sized with a round pupil. SCUTELLATION: Head scutes are normal with the following exceptions: the special­ ized rostral is large with an obtuse, transverse keel.

15 (rhinostoma) or 17 (rohdei) dorsal scale rows. Dorsal scales are smooth with apical pits. 170-190 ventral scutes; ventrals laterally angulate. Anal divided. 64-67 caudal scutes; caudals divided. DENTITION: 20-22 maxillary teeth. Maxillary and mandibular teeth are subequal in size. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is 10+ subcaudals in length. Basal portion nude with scattered spinules. Spines beginning with subcaudal 4 sharply increasing in length to subcaudal 5; diminishing in length from subcaudal 6 to 7; organ papillose with ill-d e fin e d calyces to end. Apparently single. Sulcus is simple to apex. Organ not capitate (Dowling and Jenner). GEOGRAPHIC RANGE: Paraguay and B razil. HABIT: Simophis is oviparous and feeds on rodents. GENERIC RELATIONSHIPS: No information available. REFERENCES: Boulenger, 1894; Dunn, 1928b. LEGEND FOR FIGURE 168: Geographic D istribution of Species of Simophis: I Irhinostoma rohdei

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Figure 168.

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GENUS: Siphlophis Fitzinger, 1843 TYPE SPECIES: Coluber audax Daudin CONTENT: 5 species (see LEGEND)

MORPHOLOGY: Body is compressed with a long t a i l . Maximum length: 930 mm. Max­ imum ta il length: 230 mm. Head is distinct from neck. Eye is large with a vertical pupil. SCUTELLATION: Head scutes are normal.

17-21 dorsal scale rows. Dorsal scales are smooth with 2 apical pits. 205-255 ventral scutes; ventrals angulate. Anal single. 98-118 caudal scutes. Caudals divided. DENTITION: 13-19+2 or 14-17+11 (Boulenger saw grooved postdiastemal teeth, others did not). Third to fifth, or fifth to sixth maxillary teeth greatly enlarged, followed by a diastema and smaller postdiastemal teeth. Anterior mandibular teeth strongly enlarged. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, bicapitate with a forked sulcus, spines, and medial apical awns. GEOGRAPHIC RANGE: Panama to Brazil and Bolivia. HABIT: Siphlophis is arboreal, nocturnal, and oviparous. GENERIC RELATIONSHIPS: No information available. REFERENCES: Amaral, 1935; Bailey, 1967; Boulenger, 1896; Hoge, 1964b; Prado, 1940. LEGEND FOR FIGURE 169: Geographic D istribution of Species of Siphlophis

4&cervinus 31 leucocephalus I |»l longicaudatus •v/A pulcher gjworontzowi

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85 ¥ 75 W ¥ 35 W55 LONG

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GENUS: Sordellina Procter, 1923 TYPE SPECIES: Sordellina brandon-jonesii Procter CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body is cylindrical with a short, sharply pointed ta il. Maximum length: 528 mm. Maximum t a il length: 87 mm. Head is scarcely distinct from neck. Eye is very small with a sub-elliptic pupil. SCUTELLATION: Head scutes are normal.

17 dorsal scale rows. There are no reductions in scale rows. Dorsal scales are smooth, with no apical pits. 148-150 ventral scutes. Anal is divided. 43-53 caudal scutes; caudals divided. DENTITION: 9+2 maxillary teeth. The maxillary is very short. The postdias­ temal teeth are enlarged. 14+ subequal mandibular teeth. 19 pal­ atine and 19 pterygoid teeth. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is cylindric and short (7 subcaudals long). Small spines begin at base and extend to tip of organ. Spines diminish in size toward both ends of organ, largest spines are near middle. Sulcus forks at subcaudal 5. Apex of organ with tiny spines or papillae. Hemipenis is apparently slightly bilobate. No sign of capitation. Hemipenis small, hard to see (Dowling). GEOGRAPHIC RANGE: Rio de Janeiro, Santa Catarina, Sao Paulo, and Parana, B razil. HABIT: Sordellina feeds on frogs and caecilians. Oviparous. GENERIC RELATIONSHIPS: Sordellina is a llie d to Urotheca (now Rhadinaea) , but d iffe rs in form of t a i l . In size of eye, Sordellina resembles Hydrops (Procter). REFERENCES: Hoge, 1958; Procter, 1923. LEGEND FOR FIGURE 170: Geographic D istribution of Sordellina punctata

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Figure 170.

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GENUS: Synophis Peracca, 1896 TYPE SPECIES: Synophis bicolor Peracca CONTENT: 3 species

MORPHOLOGY: Maximum length: 765 mm. Maximum t a il length: 230 mm. Body to t a i l ra tio : 0.31-0.36. Eye is medium-sized with a round pupil. SCUTELLATION: Head scutes normal with the exception of single prefrontal and loreal present or absent.

19 or 21 midbody dorsal scale rows. Dorsal scales smooth or keeled with no apical pits. Striated scales appear in the vertebral row. Anal single. DENTITION: 21 to 27 maxillary teeth. Last three rear teeth enlarged, but there is no diastema. VERTEBRAE: Hypapophyses present on posterior vertebrae. Neural spine enlarged and flattened. Zygapophyses enlarged. HEMIPENIS: Hemipenis is d is ta lly bilobed; spines in approzimately six rows, enlarged and hook-like near base, diminish in size distally and replaced by calyces with crenulated edges on lobes. Sulcus is forked. Length: 6-7 caudals. GEOGRAPHIC RANGE: Amazonian lowlands of Ecuador and Colombia. HABIT: No information available. GENERIC RELATIONSHIPS: Synophis is related to Xenopholis, Diaphorolepis, and Ninia (see Xenopholis account). A ll four genera may share a remote common ancestor (Bogert). REFERENCES: Bogert, 1964; Peters, 1960b. LEGEND FOR FIGURE 171: Geographic D istribution of Species of Synophis:

z^bicolor X la s a lle i ■ miops

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Figure 171.

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GENUS: Tachymenis Wiegmann, 1835 TYPE SPECIES: Tachymenis peruviana Wiegmann CONTENT: 6 species (see LEGEND)

MORPHOLOGY: Body is stocky, cylindrical with a medium-length ta il. Maximum length: 530 mm. Maximum t a il length: 90 mm. Body to t a i l ratio : 0.24. Head is s lig h tly d istin ct from neck. Eye is medium-sized with a vertical, or subelliptic pupil. SCUTELLATION: Head scutes are normal.

17 or 19 midbody dorsal scale rows. Dorsal scales are smooth with 1 apical p it . 134-169 ventral scutes; ventrals rounded. Anal div­ ided. 37-69 caudal scutes; caudals divided. DENTITION: 5-16+II m axillary teeth. Fangs large and d is tin c tly grooved. Pre- diastemal teeth subequal in size. Anterior mandibular teeth are longest (Boulenger). Only a few mandibular teeth, quite small. Mandibular teeth increase in length rapidly (Bailey). VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. GEOGRAPHIC RANGE: Pacific Peru and Chile; Amazonian Peru and B o livia; Surinam. HABIT: Tachymenis is terrestrial and semiarboreal. It feeds on frogs, toads, salamanders, lizard s , and rodents. I t is ovoviparous. GENERIC RELATIONSHIPS: Tachymenis is close to Coniophanes and Gomesophis (Dunn). I t is related to Tomodon, Ptychophis, Gomesophis, Pseudotomodon, and Calamodontophis (B ailey). HEMIPENIS: Hemipenis is bilobed with a forked sulcus. The body of the organ is covered with spines of subequal length. It s base only has a few minute spines, and its tip is covered by small spines which fuse at th e ir bases to give a s lig h tly calyculate appearance (Walker). REFERENCES: Amaral, 1976; Bailey, 1966; Boulenger, 1896; Dunn, 1922, 1928b; Walker, 1945. LEGEND FOR FIGURE 172: Geographic D istribution of Species of Tachymenis

af fin is y< attenuata O tarmensis

LEGEND FOR FIGURE 173: Geographic D istribution of Tachymenis peruviana

T. elongata does not appear on these maps. Its Tocality is Tablaso da Payta, Peru.

T. surinamensis does not appear on these maps. No locality data are available for this species.

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Figure 172.

3

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Figure 173.

to \---V-3 i r ^85° Tt)0 *55° Ybo W LONG

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GENUS: Tantalophis Duellman, 1958 TYPE SPECIES: Leptodeira discolor, Duellman CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body is tapered with a long t a il. Maximum length: 555 mm. Body to tail ratio: 39.4. Eye is large with a vertical pupil. SCUTELLATION: Head scutes are normal.

19 midbody dorsal scale rows. Dorsal scale rows reduced through loss of paravertebrals and sublaterals. Dorsal scales keeled with 2 apical pits. 175-180 ventral scutes. Anal divided. 80-89 caudal scutes; caudals divided. DENTITION: 12-13+2 m axillary teeth. The diastema is short and the postdiastemal teeth are somewhat enlarged. 19 mandibular teeth. 10 palatine teeth 23 (21) pterygoid teeth. Pterygoid teeth decrease posteriorly. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, bicapitate with a forked sulcus. It is short and has many longitudinal folds on the basal portion. Small spines and calyces are on the distal part. There is a weakly differentiated capitulum on each lobe. Capitulum is calyculate. Base is spinose. GEOGRAPHIC RANGE: Six miles southeast of Taxazulapam in northwestern Oaxaca, and in the upper reaches of the Balsas Basin. HABIT: Found in an arid interior valley that expands in its upper end to form a broad basin of rolling and dissected terrain. 4000-6000'. GENERIC RELATIONSHIPS: Tantalophis approaches Leimadophis in general physiognomy. I t may represent an early divergent stock of Leimadophis that has under­ gone radical changes in hemipenis and other characters. Tantalophis is related to Cryophis, Eridiphas, Hypsiglena, and Leptodeira. It is a r e lic t restricted to montane environments (Duellman). REFERENCES: Duellman, 1958, 1966 LEGEND FOR FIGURE 174: Geographic D istribution of Tantalophis discolor

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Figure 174.

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GENUS: Tantilla Baird and Girard, 1853 TYPE SPECIES: Tantilla coronata Baird and.Girard CONTENT: 49 species (see LEGEND)

MORPHOLOGY: Body is slender, small, cylindrical with a medium-length, or short tail. Maximum length: 20 inches. Head is flat and not or slight­ ly distinct from neck. Eye is small with a round pupil. SCUTELLATION: Head scutes are normal except no loreal; postoculars 2, 1-2, or 1; 6 or 7 supralabials.

15 dorsal scale rows. Dorsal scales are smooth with no apical pits. 110-190 ventral scutes; ventrals rounded. Anal single or divided. 27-73 caudal scutes; caudals divided. DENTITION: 12-14+11 m axillary teeth. Prediastemal teeth short.Fangs feebly enlarged and grooved. Mandibular teeth subequal. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is single, noncapitate, with a single sulcus, calyces and spines. GEOGRAPHIC RANGE: Kansas, Arkansas, Missouri to Nebraska, Colorado, Oklahoma, Texas, Utah, New Mexico, Nevada, C alifo rn ia, southeast to Kentucky through Florida. South of Mexican border the range extends to Peru, Para­ guay, and B razil. HABIT: Found in moist, heavily wooded slopes, on h ills, and rocky hillsides. Fossorial, nocturnal, and oviparous, Tantilla feeds on worms and centipedes. GENERIC RELATIONSHIPS: No information. REFERENCES: Amaral, 1976; Bailey, 1966b; Blanchard, 1938; Boulenger, 1896; Cope, 1886; Lema, 1978d; McCoy, 1964; McCoy, Knopf, and Walker, 1964; Savitzky and C o llins, 1971; Smith, 1942b; 1962, 1969; Smith and Smith, 1951; Smith and Williams, 1966; Wilson, 1979; Wright and Wright, n

1 9 5 7 •

NOTE: T. depperi does not appear on these maps. ^ Its distribution is unknown.

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LEGEND FOR FIGURE 175:

Geographic D istribution of Species of T a n tilla

0 albiceps •£' annulata ♦ brevicauda brevis a ja n i 77 ruficeps 1 tritaeniata ? vermiformis 0 virgata 11 \ mexicana

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Figure 175.

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LEGEND FOR FIGURE 176: Geographic D istribution of Species of T a n tilla ■iCbocourti ® bogerti :;X-calainarina A coronadoi ■ deviatrix | U |martindelcampoi miniata a morgani © s tria ta

LEGEND FOR FIGURE 177: Geographic D istribution of Species of T a n tilla /^atriceps canula (@( cuniculator ||| phrenitica rubra ‘x.'.wilcoxi

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25 N iue 176. Figure Fgr 177. Figure ! 197

LEGEND FOR FIGURE 178: Geographic D istribution of Species of T a n tilla '/#'armillata A bairdi * moesta schistosa .w-y taeniata

LEGEND FOR FIGURE 179: Geographic D istribution of Species of T a n tilla ■^Leiseni • hobartsmithi -fc yaquia

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Figure 179.

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LEGEND FOR FIGURE 180: Geographic D istribution of Species of T a n tilla •••'•alticola 3E fraseri fp longif rontalis nigra ■ petersi re tic u la ta fyj semicincta O supracincta

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Figure 180.

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LEGEND FOR FIGURE 181: Geographic D istribution of Species of T a n tilla coronata Hf o o litic a • re lic ta

LEGEND FOR FIGURE 182: Geographic D istribution of Species of T a n tilla g ra c ilis nigriceps

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IV

O

Figure 182.

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LEGEND FOR FIGURE 183:

Geographic D istribution of T a n tilla melanocephala

LEGEND FOR FIGURE 184:

Geographic D istribution of T a n tilla utahensis

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LAT 183. Figure 5®'T5 5 # 5 W 115* TF5* ' « «5* «5* 95*® LONG iue 184. Figure 201

GENUS: Tantillita Smith, 1941 TYPE SPECIES: Tantilla lintoni Smith CONTENT: 2 species (see LEGEND)

MORPHOLOGY: Small snake with a short ta il. No further information. SCUTELLATION: Head scutes are normal except no loreal and temporals 1+1.

15 dorsal scale rows. Dorsals smooth with no apical pits. DENTITION: 22-25 maxillary teeth. Maxillary teeth subequal-sized. Posterior teeth not or only slightly enlarged. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis extends to subcaudal 7. Spinulose proximally, followed by fringed flounces which grade into fringed calyces (subcaudals 4-5) which extend to tip . Hemipenis small, poorly preserved, sulcus cut. Unable to determine i f sulcus is simple or forked. Only specimen other than type (Dowling). GEOGRAPHIC RANGE: Chiapas and Guatemala. HABIT: No information available. GENERIC RELATIONSHIPS: No information available. REFERENCES: Smith, 1941a; Smith and T ayloi, 1944, 1966. LEGEND FOR FIGURE 185: Geographic D istribution of Species of T a n tillita A brevissima ;<9 lin to n i

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100* V 90° V

Figure 185.

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GENUS: Thamnodynastes Wagler, 1830 TYPE SPECIES: Natrix punctatissimus Wagler CONTENT: 5 species (see LEGEND)

MORPHOLOGY: Body is cylin d rical with a medium-length or rather long t a i l . Max­ imum to ta l length: 760 mm. Maximum t a i l length: 170 mm. Head is d is tin c t from neck. Eye is large with a v e rtic a l pupil. SCUTELLATION: Head scutes are normal.

17 or 19 dorsal scale rows. Dorsal scales are smooth or keeled with apical p its . 137-160 ventral scutes; ventrals rounded. Anal div­ ided. Caudals 48-78; caudals paired. DENTITION: 13-18+11 m axillary teeth. Prediastemal teeth are subequal in size. Fangs are enlarged. Mandibular teeth are subequal in size. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is short (8 subcaudals) and s lig h tly bilobed. Basal por­ tion nude, then approximately three rows of large spines angling up from the sulcus. Spines diminish d is ta lly (4th subcaudal) and gradually grade into uniform, small, slightly papillate calyces ( 6th subcaudal). Calyces continue to apices of short lobes. Sulcus forks at subcaudal 7. Calyces between forks of sulcus and a ll the way around the organ. No sign of capitation or semicap­ ita tio n . Cope's figure is approximately correct (Dowling and Jen- n e r). GEOGRAPHIC RANGE: Caribbean coast of South America to northern Argentina. HABIT: No information available except that Thamnodynastes bears living young . GENERIC RELATIONSHIPS: Thamnodynastes is related to Tachymenis, Tomodon, Ptychophis, Gomes- ophis, Pseudotomodon, and Calamodontophis (B a ile y ). REFERENCES: Bailey, 1966b; Boulenger, 1896; Dunn, 1928b; Peters, 1960a. LEGEND FOR FIGURE 186: Geographic D istribution of Species of Thamnodynastes ''$> chimanta pallidus (g) ru tilu s /fy s tr ig ilis ggstrlgatus

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Figure 186.

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GENUS: Tomodon Dumeril and Bibron, 1853 TYPE SPECIES: Tomodon dorsaturo Dumeril, Bibron, and Dumeril CONTENT: 3 species (see LEGEND)

MORPHOLOGY: Body is cylin d rical with a medium-length or short t a il. Maximum length: 610 mm. Maximum t a il length: 150 mm. Head is d istin ct from neck. Eye is medium-sized with a round pupil. SCUTELLATION: Head scutes are normal.

15, 17, or 19 dorsal scale rows. Dorsal rows oblique, smooth with apical p its . 134-147 ventral scutes; ventrals rounded. Anal div­ ided. 31-62 caudal scutes; caudals divided. DENTITION: 5-8+II maxillary teeth. The maxillary is short, and the fangs are enormous and doubly grooved. They are 70% of the length of the maxillary bone. The anterior mandibular teeth are a little larger than the posterior mandibular teeth. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is bilobed, noncapitate with a forked sulcus, spines, and calyces. GEOGRAPHIC RANGE: From central B razil to Paraguay, Uruguay, and north-central Argentina. HABIT: Tomodon is arboreal and ovoviparous. It feeds on lizards and small rodents. GENERIC RELATIONSHIPS: Tomodon is related to Tachymenis, Ptychophis, Pseudotomodon, Cala- modontophis, Gomesophis, and Thamnodynastes. The anterior max­ illa r y teeth of Tomodon are in the process of being lost en tirely and large fangs w ill remain as the only m axillary dentition (B ailey). REFERENCES: Amaral, 1976; Bailey, 1966b; Boulenger, 1896; Dunn, 1928b. LEGEND FOR FIGURE 187: Geographic D istribution of Species of Tomodon '^degner ^dorsatus ^||ocellatus 7 I

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Figure 187.

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GENUS: Tretanorhinus Dumeril, Bibron and Dumeril, 1854 TYPE SPECIES: Tretanorhinus varibllis Dumeril, Bibron and Dumeril CONTENT: 4 species (see LEGEND)

MORPHOLOGY: Body is cylind rical with a medium-length t a i l. Maximum length: 680 mm. Maximum t a il length: 160 mm. Head is s lig h tly distinct from neck. Eye is small with a round to oval pupil. SCUTELLATION: Head scutes are normal with these exceptions: 3,2, or 1 prefrontal; nostril directed upward, pierced between two nasals.

17-21 dorsal scale rows. Dorsal scales reduced through loss of paravertebrals. Dorsal scales keeled and striated with no apical p its . 131-177 ventral scutes; ventrals rounded. Anal divided. 50-85 caudal scutes; caudals divided. DENTITION: 27-30 maxillary teeth. Maxillary teeth subequal in size. Mandib­ ular teeth subequal in size. VERTEBRAE: Hypapophyses present posteriorly (Boulenger); hypapophyses not pre­ sent on posterior vertebrae (Dowling). Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is single or slightly bilobed, capitate with a forked sulcus. The calyculate area is capitate; the sulcus forks within the calycualte area; 4 basal hooks; between hooks and calyculate area are about 4 cross rows (10 longitudinal rows) of rather uniform, smaller spines. GEOGRAPHIC RANGE: Extreme southern Mexico to Colombia and Ecuador, Cuba, Is la Pinos, and Caymans in the A n tille s . HABIT: Tretanorhinus is nocturnal, aquatic, and possibly marine. It feeds on fishes, frogs, and tadoples (Scott). GENERIC RELATIONSHIPS: Tretanorhinus v a rib ilis appears to be a recent immigrant from Cen­ t r a l America to Cuba. Tretanorhinus* hemipenis is most lik e some forms of Rhadinaea-Coniophanes-Trimetopon. Its dentition, scales, and hypapophyses are sim ilar to N in ia. Hemipenis and hypapophyses are sim ilar to Amastridium (Wood). REFERENCES: Dunn, 1939; Scott, 1969; Wood, 1939 t fV

I ' h s ' A

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LEGEND FOR FIGURE 188: Geographic Distribution of Species of Tretanorhinus

:&'• nigroluteus taeniatus ^ varibilis

LEGEND FOR FIGURE 189:

Geographic D istribution of Tretanorhinus mocquardi

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LAT 2 00* V 00* iue 188. Figure iue 189. Figure CJ ooc o io V 70° o 206

GENUS: Trimetopon Cope, 1885 TYPE SPECIES: Ablabes gracilis Gunther CONTENT: 9 species (see LEGEND)

MORPHOLOGY: Body is elongate, cylin d rical with a medium-length t a i l . Maximum length approximately 300 mm. Maximum t a il length: 77 mm. Head is scarcely distinct from neck. Eye is small with a round pupil. SCUTELLATION: Head scutes are normal except 1 prefrontal fused with other head scutes; postocular 1 or 2.

15 or 17 dorsal scale rows. Dorsal scales smooth with indistinct apical p its . 141-149 ventral scutes; ventrals rounded. Anal div­ ided. 60-65 caudal scutes; caudals divided. DENTITION: Less than 14 maxillary teeth. Maxilla is short. The maxillary teeth gradually increase in length to the last. No diastema. Mand­ ibular teeth are subequal-sized. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. HEMT.PENIS: Hemipenis extends to subcaudal 5-6. Spinulose proximally: rows of spines from subcaudal 2 to near tip . Sulcus forks at subcaudal 3. Small p a p illa te calyces extend down to fork. D istin ct cap it- ulum on asulcate side. Not or only slightly bilobed. Hemipenis very small (Dowling). GEOGRAPHIC RANGE: Guatemala and Costa Rica and Canal Zone of Panama: 60-2210 m. HABIT: Fossorial, Trimetopon probably feeds on invertebrates (S cott). GENERIC RELATIONSHIPS: Trimetopon is possibly related to Rhadinaea and Enulius. REFERENCES: Boulenger, 1894; Dunn, 1928b; Scott, 1969. LEGEND FOR FIGURE 190: Geographic D istribution of Species of Trimetopon. ® barbouri gracile o hannsteini * pilonaorum /•y/pliolepis ■ sim ile ❖ slevin i • verapacis A viquezi

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e 90° V.

Figure 190.

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GENUS: Trimorphodon Cope, 1861 TYPE SPECIES: Lycodon lyrophanes Cope CONTENT: 10 species (see LEGEND)

MORPHOLOGY: Body is compressed with a medium-length t a i l. Size is large, often exceeding 1000 mm. Head is d istin ct from neck. Eye is medium­ sized with a vertical pupil. SCUTELLATION: Head scutes are normal with the following exceptions: 2-3 loreals; uaually 3 pre- and 3 postoculars; a subocular below the preocular.

23 midbody dorsal scale rows. Dorsal scales are smooth with 2 apical pits. 205-275 ventral scutes. Ventrals are slightly oblique. Anal divided. 61-102 caudal scutes. DENTITION: 10-11+11 m axillary teeth. Fangs are enlarged and grooved Predias- temal teeth decrease posteriorly in size. Anterior mandibular teeth are strongly enlarged. VERTEBRAE: Hypapophyses not present on posterior vertebrae*. Neural spine not enlarged. Zygapophyses not enlarged. *Hypapophyses present on the fir s t 54 vertebrae. HEMIPENIS: Hemipenis is single and capitate with a single sulcus. It is long with flounces. The slender basal portion is devoid of spines. There are no spines on the d is ta l part. Capitulum is flounced and has minute spines. GEOGRAPHIC RANGE: Southwestern US south to western Nicaragua. HABIT: Trimorphodon is terrestrial and occasionally arboreal, nocturnal, and oviparous. It feeds on lizards, birds and mammals (Scott). GENERIC RELATIONSHIPS: Trimorphodon is probably related to Hypsiglena, Eridiphas, and Leptodeira (Scott). REFERENCES: Boulenger, 1896; Duellman, 1958b, Dunn, 1928b; Leviton and Tanner, 1960; Scott, 1969; Smith, 1941; Taylor, 1939. LEGEND FOR FIGURE 191: Geographic D istribution of Species of Trimorphodon ||<£| biscutatus lambda * lyrophanes o vandenburgi □ vilkinsoni

LEGEND FOR FIGURE 192: Geographic D istribution of Species of Trimorphodc A c o lla ris ■O':, f asciolata 141 forbesi 351latifasciata a tau

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\5®kj 2 iue 191. Figure iue 192. Figure oa 208

GENUS: Tripanurgos Fitzinger, 1843 TYPE SPECIES: Coluber leucocephalus Mikan CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body is compressed with a long t a i l . Maximum length: 1080 mm. Maximum t a i l length: 250 mm. Head is d istinct from neck. Eye is large with a vertical pupil. SCUTELLATION: Head scutes are normal.

19+17+15 dorsal scale rows. Dorsal scales reduced through loss of f ir s t through fourth rows. Dorsal scales smooth, s lig h tly oblique with 2 apical pits. Vertebral row strongly enlarged. 228-258 vent­ ral scutes; ventrals angulate. Anal single. 80-125 caudal scutes; caudals divided. DENTITION: 13-15+11 m axillary teeth. Anterior prediastemal teeth larger than posterior prediastemal teeth. Mandibular teeth gradually decrease in size (anterior teeth longest). VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed and bicapitate with a forked sulcus. The bi- lobed portion extends to subcaudal 8 . Short basal area with a few small spines on an otherwise smooth surface. The basal portion is longitudinally ridged. The central portion of the organ has large spines. The sulcus bifurcates in the proximal part of the central portion. The distal portion of the organ has papillate calyces. Lateral and medial ridges join at apex to form an ele­ vated apical disk. Medial apical awns are present. GEOGRAPHIC RANGE: Coastal strip of Brazil from Rio de Janeiro (city) to Sergipe. Mouth of Amazon and Central B olivia to Trinidad and Panama. HABIT: Tripanurgos is arboreal, nocturnal, and oviparous. It feeds on frogs and lizards. GENERIC RELATIONSHIPS: Tripanurgos is a member of the Pseudoboini (B a ile y ). REFERENCES: Amaral, 1976; Bailey, 1967; Downs, 1961; Savage, 1966. t fW LEGEND FOR FIGURE 193: N / Geographic D istribution of Tripanurgos compressus |

A Q M K II M I I /

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v 75° 65 'W 55" V. -15' V. Tl LONG

Figure 193.

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GENUS: Tropidodipsas Gunther, 1858 TYPE SPECIES: Tropidodipsas fasciata Gunther CONTENT: 9 species (see LEGEND)

MORPHOLOGY: Body is cylin d rical or compressed with a medium-length t a i l. Maxi­ mum length: 415 mm. Maximum t a il length: 80 mm. T a il is 1/6 of to ta l length. Head is d istin ct from neck. Eye is large or medium-sized, with a su b ellip tic pupil. SCUTELLATION: Head scutes are normal except 0-4 preocular; 2 (1) postoculars; 6-7 supralabials, 6-9 infralabials.

15 or 17 dorsal scale rows. Dorsal scales smooth or feebly keeled with 0 or 2 apical p its . 130-199 ventral scutes; ventrals rounded. Anal single. 30-73 caudal scutes; caudals divided. DENTITION: 8-10 or 12-18 m axillary teeth; m axillary teeth decrease in size posteriorly. 12-13 mandibular teeth. 6-7 palatine and 12-15 ptery­ goid teeth. Mandibular, palatine, and pterygoid teeth decrease in size posteriorly. VERTEBRAE: No information available. HEMIPENIS: Hemipenis is single, capitate, with a forked sulcus. Basal portion has 4 large and several small falcate spines. The middle portion of the organ is spinose. The apex is undivided and calyculate with large papillae on calyces. Sulcus forks in calyculate region. Length: 8 subcaudals. GEOGRAPHIC RANGE: Mexico and Central America. HABIT: Tropidodipsas is arboreal, terrestrial and nocturnal. It feeds on snails and slugs. I t is widespread in the Tropical Zone with the exception of the pine belt (Scott). GENERIC RELATIONSHIPS: Tropidodipsas is related to the dipsadines (Scott). REFERENCES: Cope, 1863; Dunn, 1928 b; Scott, 1967: Smith, 1943; Stuart, 1942. LEGEND FOR FIGURE 194: Geographic D istribution of Species of Tropidodipsas -rs-fischeri ;$’ sarto ri LEGEND FOR FIGURE 195: Geographic D istribution of Species of Tropidodipsas ® fasciata A kidderi * macdougalli'» T occidentalis v Q philippi 3 guerroensis /!)! tecpanecus

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' s

I -

100 V 90 W 80 V

Figure 194.

Figure 195.

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GENUS: Tropidodryas Fitzinger, 1843 TYPE SPECIES: Philodryas serra Schlegel CONTENT: 2 species (see LEGEND)

MORPHOLOGY: Body is cylindrical or compressed with a lcr,j ta il. The tip of the tail has 8 rows of flared scales. Maximum length: 1236 mm. Maximum t a il length: 219 mm. Head is d istin ct from neck. Eye is large or medium-sized with a round pupil. SCUTELLATION: Head scutes are normal with the following exceptions: temporals are small, scale like, 2, 2+3, or 4; 5 infralabials.

21 midbody dorsal scale rows. Dorsal scales smooth or keeled with 2 apical p its . 179-244 ventral scutes; ventrals rounded. Anal single or divided. 88-106 caudal scutes. DENTITION: 13-17+11 m axillary teeth. Prediastemal teeth subequal in size. Fangs weakly grooved. 20-30 mandibular teeth. Anterior mandibular teeth are longest. 7 palatine teeth. Anterior palatine teeth are always larger than anterior maxillary teeth and equal to or larger than the postdiastemal maxillary teeth. 15-18 pterygoid teeth. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, bicapitate with a forked sulcus. Calyces are on the outer surfaces of the lobes. Spines extend around the bor­ der of the calyculate area. No large spines on the lower half of the unlobed surface. Asulcate surface is acalyculate with spinules at the base on the lobes. GEOGRAPHIC RANGE: Southeastern Brazil, states of Rio de Janeiro, Parana, Sao Paulo, Minas Gerais, Santa Catharina, and Espirito Santo. HABIT: Tropidodryas is found in evergreen tropical rainforest and deciduous mesophytic subtropical forest which has numerous evergreen species. It is arboreal, diurnal, and oviparous and feeds on frogs, lizards, and birds. GENERIC RELATIONSHIPS: No information available. REFERENCES: Amaral, 1976; Thomas and Dixon, 1977. > / t u . LEGEND FOR FIGURE 196: Geographic D istribution of Species of Tropidodryas > ® serra V f • striaticeps

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Figure 196.

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GENUS: Umbrlvaga Roze, 1964 TYPE SPECIES: Umbrlvaga mertensi Roze CONTENT: 3 species (see LEGEND)

MORPHOLOGY: Maximum length: 392 mm. Maximum t a il length: 102 mm. Body to tail ratio: 0.259. Pupil round. SCUTELLATION: Head scutes normal.

15-17 dorsal scale rows. Dorsal scales smooth with no apical pits. 122-154 ventral scutes. Anal divided. 29-60 caudal scutes; caudals divided. DENTITION: 6-12+2 maxillary teeth. Posterior maxillary teeth are enlarged, lan­ cet-shaped, and almost horizontal. 11 mandibular teeth, nearly equal in length. 1-7 palatine teeth which diminish in length. 6-13 ptery­ goid teeth which diminish in length. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is bilobed and disked with a forked sulcus. It is entirely covered with spines in 8-9 longitudinal rows. The spines are very large, some are one subcaudal long. The very long spines are con­ fined to four rows. The rows of spines extend to the base of the organ where they form large basal spines or hooks. Each lobe te r­ minates in an apical disk, comprised of smaller spines. Length: extends to 10th subcaudal; bifurcates at 6th; branches near 4th. GEOGRAPHIC RANGE: Parque Nacional Henri P it t ie r , Estado de Aragua, Venezuela. Also in Colombia, Ecuador, and Peru. HABIT: Reptile eggs found in the stomach of U. mertensi (Markezich and Dixon). GENERIC RELATIONSHIPS: Umbrivaga is related to Leimadophis, Liophis, Lygophis, Dromicus, and Rhadinaea although its dentition d iffe rs from these genera. REFERENCES: Markezich and Dixon, 1979; Roze, 1964. LEGEND FOR FIGURE 197: Geographic D istribution of Species of Umbrivaga ■O- mertensi (fl pyburni (TV 0 pygmaeus » A

* 7 ? ^ ,

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GENUS: Uromacer Dumeril and Bibron, 1853 TYPE SPECIES: Uromacer catesbyi CONTENT: 4 species (see LEGEND)

MORPHOLOGY: Body is slender, very elongate with a long ta il. Maximum length: 1310 mm. Maximum t a l l length: 580 mm. Head is d istin ct from neck. Eye is medium with a round pupil. SCUTELLATION: Head scutes are normal except sharply projecting rostral.

11-19 dorsal scale rows. Dorsal scales are smooth with no apical pits. 162-212 ventral scutes; ventrals angulate. Anal is divided. 165-214 caudal scutes; caudals divided. DENTITION: 16-18+2 maxillary teeth. Postdiastemal teeth very large. Anterior mandibular teeth are longest. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spina not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, semicapitate with a forked sulcus. I t is similar to that of Hypsirhynchus, but is shorter. It is more heavily spinose than members of Maglio’ s cantherigerus group, and the apical papillae on its sulcate surface extend further basally (to the point of division of the sulcus). Calyces are present. GEOGRAPHIC RANGE: Hispaniola, Tortue Island, Vache Island, Gonave Island, and Beata Island. HABIT: Uromacer is arboreal and feeds on frogs. GENERIC RELATIONSHIPS: Uromacer may be derived from an early form of Hypsirhynchus ferox which existed before the latter achieved present specializations. All but U. catesbyi are long and slender with arboreal adaptations. REFERENCES: Boulenger, 1894; Cochran, 1941; Dunn, 1920, 1928b; Maglio, 1970. LEGEND FOR FIGURE 198: Geographic D istribution of Species of Uromacer

• dorsalis •$-. f renatus \V oxyrhynchus

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o 66° W

Figure 198.

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GENUS: Uromacerina Amaral, 1929 TYPE SPECIES: Uromacer ricardini Peracca CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body is slender with a long t a i l . Maximum length: 720 mm. Max­ imum t a il length: 340 mm. Head is d istin ct from neck. Eye is large or medium-sized with a round pupil. SCUTELLATION: Head scutes are normal.

15 dorsal scale rows. Dorsal scales are finely striated with no apical pits. The vertebral row is enlarged. 141-157 ventral scutes; ventrals are slightly angulate. Anal is divided. 145-180 caudal scutes; caudals divided. DENTITION: 23-25+2 maxillary teeth. The last two teeth are a little longer than the prediastemal teeth. Mandibular teeth are numerous. The anterior teeth are a little longer than the posterior teeth. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. HEMIPENIS: Hemipenis is bilobed, semicapitate with a forked sulcus, spines and calyces. GEOGRAPHIC RANGE: Estado de Sao Paulo, B ra zil. HABIT: Uromacerina is arboreal and feeds on lizard s. GENERIC RELATIONSHIPS: No information available. REFERENCES: Amaral, 1929; Hoge, 1957c; Lema, 1973; Peracca, 1897a. LEGEND FOR FIGURE '199: Geographic D istribution of Uromacerina ric a rd in ii

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Figure 199.

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GENUS: Waglerophis Romano and Hoge, 1972 TYPE SPECIES: Ophis merremii Wagler, 1824 CONTENT: 1 species (see LEGEND)

MORPHOLOGY: Body is depressed with a short t a i l. Maximum to ta l length: 1040 mm. Maximum t a il length: 130 ims. Head is d istin ct from neck. Eye is large with a round pupil. SCUTELLATION: Head scutes are normal except 1-3 postoculars; 1-2 suboculars.

19 dorsal scale rows. Dorsal scales are smooth with apical pits. 132-157 ventral scutes. Anal usually divided; rarely single. 38-48 caudal scutes. DENTITION: 6-7+2 m axillary teeth. Mandibular teeth subequal in size. HEMIPENIS: Hemipenis is disked. VERTEBRAE: Hypapophyses are not present on posterior vertebrae. Neural spine is not enlarged. Zygapophyses are not enlarged. GEOGRAPHIC RANGE: Guyanas, Brazil, Bolivia, Paraguay, central and northern Argentina. HABIT: Waglerophis is te rre s tria l and oviparous. I t feeds on toads. GENERIC RELATIONSHIPS: No information. REFERENCES: Boulenger, 1894; Amaral, 1976. LEGEND FOR FIGURE 200: Geographic D istribution of Waglerophis merremii

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Figure 200.

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GENUS: Xenodon Boie, 1827 TYPE SPECIES: Coluber severus Linnaeus CONTENT: 7 species (see LEGEND)

MORPHOLOGY: Body is c y lin d rical, depressed with a medium-length or short t a il. Maximum length: 548 mm. Maximum t a il length: 90 mm. Head is dis­ tinct from neck. Eye is large with a round pupil. SCUTELLATION: Head scutes are normal with the following exceptions: no subocular; 2 postoculars, 7 upper- and 9 lower labials.

17, 19, or 21 dorsal scale rows. Dorsal scales are smooth, in oblique rows with 1 apical pit. 126-168 ventral scutes; ventrals rounded or angulate. Anal single or divided (guentheri)♦ 35-42 caudal scutes; caudals divided. DENTITION: 6-15+II maxillary teeth. Prediastemal teeth increase posteriorly. Fangs are strongly enlarged. Mandibular teeth subequal in length. VERTEBRAE: Hypapophyses not present on posterior vertebrae. Neural spine not enlarged. Zygapophyses not enlarged. HEMIPENIS: Hemipenis is bilobed, disked with a forked sulcus. Basal section is shorter than either lobe. Sulcus divides at point somewhat nearer base than point of bifurcation. Entire organ, except for base, is spinose. Largest spines are near the base. GEOGRAPHIC RANGE: Mexico through Central America, east of Andes in South America to Argentina. 0-1170 mm. HABIT: Xenodon is terrestrial, riparian, diurnal, and oviparous. It feeds on frogs, toads, tadpoles, birds, and rodents. GENERIC RELATIONSHIPS: Dunn (1944) believes that Xenodon is related to Leimadophis, Lygophis, and Dromicus (S co tt). REFERENCES: Boulenger, 1894; Hoge, 1958, 1964; Scott, 1969; Smith, 1940. LEGEND FOR FIGURE 201: Geographic D istribution of Species of Xenodon bertholdi .<&>'• mexicanus LEGEND FOR FIGURE ’ 202: Geographic D istribution of Species of Xenodon ,'A; guentheri neuwiedii <(?;.rhabdocephalus t$‘. severus

X. suspectus is not shown on these maps. Its lo c a lity is Lago Jose Assu, Brazil, and distribution is eastern Peru

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“ 1

F ig u re

'loefiaf *6° 1F6° 156° *6° W6° «6° W LONG

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GENUS: Xenopholis Peters, 1869 TYPE SPECIES: Xenopholis Braconnieri Peters CONTENT: 3 species (see LEGEND)

MORPHOLOGY: Body is cylindrical with a short ta il. Maximum length: 330 mm. Maximum ta il length: 55 mm. Head is slightly distinct from neck. Eye is small with a vertical or round pupil. SCUTELLATION: Head scutes are normal except single prefrontal.

17 dorsal scale rows. No reduction of scale rows. Dorsal scales are smooth with no apical pits. 128-141 ventral scutes; ventrals are rounded. Anal is single. 28-39 caudal scutes; caudals divided. DENTITION: 14+11 maxillary teeth. Fangs are modestly enlarged. Mandibular teeth are subequal in length. VERTEBRAE: Hypapophyses are present on posterior vertebrae. Neural spines are enlarged, forming rugose shields divided by a median groove. Zyga- pophyses are enlarged. HEMIPENIS: Hemipenis is bilobed or single with a forked sulcus. It has spines which diminish in size distally and gradually give way to calyces on the paired lobes. Enlarged spines flank the sulcus where i t bifurcates. Length: 9 caudals; sulcus bifurcates at 8th caudal. GEOGRAPHIC RANGE: Amazonian B olivia, Peru, Ecuador, and B razil. HABIT: No information available. GENERIC RELATIONSHIPS: Xenopholis * grooved teeth, e llip tic a l pupil, blotched pattern a ll point to the early divergence from snakes ancestral to Synophis. Xenopholis, Synophis, and Diaphorolepis are a ll related (Bogert). Bailey believes X- reticulatus and X. undulatus may not be dist­ inguishable. REFERENCES: Bailey, 1966b; Bogert, 1964; Boulenger, 1896, Cope, 1894; Peters, 1 9 6 0 a . LEGEND FOR FIGURE 203: Geographic D istribution of Species of Xenopholis 'i: reticulatus ®/// scalaris A undulatus

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DISCUSSION

A. GENERA DELETED FROM TRIBAL ALLOCATIONS

1. Genera Transferred to Subfamily Colubrinae

The genera Scolecophis and Simophis previously were

assigned to Tribe Alsophiini (Dowling and Duellman, 1978),

although their hemipenes had not been described. An

examination of the hemipenes of these genera has revealed

that these two genera have single, spinose hemipenes

with simple sulci and distal calyces. Neither has a cap­

itate hemipenis. Members of both genera lack the distinc­

tive features of the xenodontine hemipenis: forked sul­

cus or capitation. On this basis, Scolecophis and Simophis

are transferred to subfamily Colubrinae and are not

considered further.

Tantilla previously was allocated to the Tribe Dipsad-

ini (Dowling and Duellman, 1978). A reexamination of the

hemipenis of some species of Tantilla shows that it, too, is

a colubrine. Tantilla*s hemipenis is single, noncapitate,

and spinose with a simple sulcus and distal calyces. Tan­

tilla is therefore transferred to the subfamily Colubrinae.

Trimorphodon was recognized as a member of Tribe Dip-

sadini (Dowling and Duellman, 1978). The hemipenis of

Trimorphodon, because it is long and single with distal,

spinulose flounces, a simple sulcus, and no calyces, lacks

the features necessary to qualify for xenodontine status.

Trimorphodon is also transferred to subfamily Colubrinae.

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2. Genera With Flounced Hemipenes

Conophis, Ialtris, and Pseudoeryx have bands of floun­

ces that encircle the medial portion (Pseudoeryx), or ap­

ices (Conophis, Ialtris), of otherwise calyculate (Pseudo­

eryx) , or spinose (Conophis, Ialtris) hemipenes. Although

flounces are a common ornament of the hemipenes of most

boids, some anilids, other colubrids, elapids, and viper-

ids (Dowling and Savage, 1960), they are an unusual orna­

ment for xenodontine hemipenes. To complicate the problem,

four species of Atractus (A. badius group) and two species

of Coniophanes (C. imperialis and C. bipunctatus) also have

flounced hemipenes. The other species of Atractus have

spinose hemipenes, whereas the other species of Coniophanes

have capitate hemipenes. This suggests that both Atractus

and Coniophanes, as presently recognized, are composite gen­

era and should be revised, with new genera erected to acc­

omodate the radical differences in hemipenes between cer­

tain members of the genera.

Because the additional investigations necessary to cor­

rectly assign Conophis, Ialtris, Pseudoeryx, and certain

species of Atractus and Coniophanes to xenodontine tribes

are beyond the scope of the present work, these forms are

excluded from the present tribal allocations.

3. Genera With Inadequate Data

Ditaxodon, Elapomo.jus , Hydromorphus , Lioheterophis,

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Parapostolepis, Paraptychophis, Platynion, and Tantillita

are excluded from this analysis of xenodontine tribal all­

ocations because information about the configuration of

their hemipenes could not be obtained.

The hemipenis of a specimen of Tantillita was examined.

It was found to have proximal spines, fringed flounces, and

calyces with no sign of capitation. The sulcus, however,

had been damaged in a previous dissection of the single

specimen available, and it was impossible to discern whet­

her it was forked or simple. If its hemipenis has a fork­

ed sulcus, Tantillita might be grouped with those xenodon-

tines which have a flounced hemipenis. If it is simple,

Tantillita belongs to the subfamily Colubrinae.

Because the single specimen upon which the original

description of Elapomojus was based has been lost and the

hemipenis was not described, any tribal allocation will

have to wait until another specimen is discovered.

The hemipenis of Tantalophis has been reported in

the literature as bilobed, with a forked sulcus, proximal

spines, and distal calyces (Duellman, 1958c). Since the

calyces are restricted to the apices of both lobes, on

the basis of this description, Tantalophis would appear

to fall into Tribe Pseudoboini. Duellman's figure was

made from a non-everted hemipenis. HISS drawings, made

of an everted organ, on the other hand, show a radically

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different configuration. Although the hemipenis is bi-

lobed with a forked sulcus, the bicapitation is poorly

developed and the hemipenis does not have a typically

pseudoboine appearance. Tribal allocation of Tantalophis

is therefore deferred until additional data are available

to clarify its tribal relationships.

4. Summary of Genera Deleted From Tribal Allocations

The genera deleted from xenodontine tribal allocations

include the following:

a. Scolecophis, Simophis, Tantilla, and Trimorphodon

are transferred to Subfamily Colubrinae.

b. Conophis, Ialtris, Pseudoeryx, and species of

Atractus and Coniophanes which have flounced hemipenes

cannot be assigned to xenodontine tribes.

c. Lack of adequate hemipenis description prevents

tribal allocation of Ditaxodon, Elapomojus, Hydromorphus,

Lioheterophis, Parapostolepis, Paraptychophis, Platynion,

Tantalophis, and Tantillita.

B. TRIBAL ALLOCATIONS

Analysis of the hemipenial information for the 73 rem­

aining xenodontine genera reveals seven basic patterns

within the group. Tribes have been erected to accommo­

date each of these distinctive patterns. Table 7 details

the hemipenial information for each tribe. The seven

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE 7: HEMIPENES OF SUBFAMILY XENODONTINAE

Sulcus ______Shape Capitation______Ornamentation F_ S Si SB B_ N_ S_ B_ c_ D __S _C MA A Al8ophiini (11) 11 - - 1 10 - 11 -- - 11 11 1 Diaphorolepini (10) 10 - - 3 7 10 - -- - 10 - - - Dipsadini (13) 12 1? 7 5 i -- - 13 - 13 13 Leptodeirini (4) - 4 4 - - - tm - 4 - 4 4 - Philodryini (16) 15 - 4 2 9 15 - - - - 15 15 - Pseudoboini (10) 10 - - - 10 - - 10 - - 10 10 - - Xenodontini (9) 9 -- 1 8 - - -- 9 9 9 --

Abbreviations: Sulcus: F**forked, S=simple; Shape: Si^single, SB=slightly bilobed, B«bilobedf Capitation: N=noncapitate, S=semicapitate, B^bicapitate, C»capitate, D=disked; Ornamentation: S=spines, C®calyces, MA=medial apical awns( A=awns.

N o t e : Numbers Indicate the number of genera in each category. 222

xenodontine hemipenial patterns are as follows:

1. noncapitate, slightly or distinctly bilobed, forked

sulcus, entirely spinose, no calyces (Tribe Diaphorolepini).

2. noncapitate, slightly or distinctly bilobed or single,

forked sulcus, proximal spines, and distal calyces (Tribe

Philodryini).

3. Semicapitate, slightly or distinctly bilobed, forked

sulcus, proximal spines, distal calyces (Tribe Alsophiini).

4. Fully capitate, single, slightly or completely bilobed,

forked sulcus, proximal spines, capitation of calyces

(Tribe Dipsadini).

5. Fully capitate, single or bilobed to single, simple

sulcus, proximal spines, capitation of calyces (Tribe Lep-

todeirini).

6 . Bicapitate (capitation confined to the apices of a bi­

lobed hemipenis), forked sulcus, proximal spines, medial

apical awns (Tribe Pseudoboini).

7. Disked, bilobed or slightly bilobed, proximal spines,

no calyces, forked sulcus (Tribe Xenodontini).

The seven xenodontine tribes are discussed at length in

the sections which follow.

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1. Tribe Alsophiini

The tribe Alsophiini is composed of eleven genera and

53 species of xenodontine snakes which have the Greater

Antilles as a present day center of distribution.

DEFINITION: Tribe Alsophiini is defined by possession of

a bilobed, semicapitate hemipenis with proximal spines,

distal calyces, and forked sulcus. The sulcus forks below

the semicapitation (Table 12).

a. Ecology

The available ecological information indicates that

three alsophiine genera are arboreal, three are aquatic, one

is terrestrial, and one is semifossorial (Table 8)- No

ecological information is available for three genera. Diet­

ary information indicates that a great diversity of verte­

brate prey is consumed by members of the Alsophiini. Het-

erodon, though mainly a toad-feeder, is omnicarnivorous,

including frogs, toads, salamanders, lizards, snakes, birds,

mammals, and insects (?) in its diet. One semiarboreal

Lesser Antillean form of Alsophis (A. ater) is known to feed

on bats. The three aquatic genera, Farancia, Helicops, and

Hydrodynastes, feed on fishes, frogs, toads, and large sal­

amanders. The arboreal Hispaniolan and Brazilian genera,

Uromacer and Uromacerina, feed on frogs and lizards, res­ pectively.

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TABLE 8: TRIBE ALSOPHIINI - ECOLOGY

Genus Information

Alsophis semiarboreal; feeds on bats (1 species)

Antillophis none

Arrhyton none

Darlingtonia semifossorial

Farancia aquatic; feeds on eels, Siren, Amphiuma

Helicops aquatic; feeds on fishes; oviparous or fac­ ultatively ovoviviparous

Heterodon terrestrial, diurnal; feeds on frogs, toads, salamanders, lizards, snakes, birds, mammals, insects (?) Hydrodynastes aquatic; feeds on fishes, frogs, toads

Hypsirhynchus none

Uromacer arboreal; feeds on frogs

Uromacerina arboreal; feeds on lizards

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b. Morphology

Morphological data reveal basic similarities within

the tribe (Table 9). Body shape in general is cylindrical,

although variations of this pattern occur. In the arbor­

eal genera Alsophis, Uromacer, and Urotnacerina, the tail is

long to very long. The terrestrial genus Heterodon has a

stout, subcylindrical body with a short tail. Total len­

gths of members of the Alsophiini range from 297 mm to over

two meters. Tail length ranges from 105 to 580 mm. Eyes

in alsophine genera vary from large to small, but all mem­

bers of the tribe have a round pupil. The number of dorsal

scale rows ranges from 11 to 25. Only one genus is rep­

orted to have scale row reductions: in Hydrodynastes the

dorsal scale rows are reduced through loss of the paraverte­

bral rows. The majority of alsophiines have smooth dorsal

scales, although there are some exceptions. Helicops'

scales are smooth to strongly keeled, Heterodon has keeled

scales, and Uromacerina has feebly striated scales with the

vertebral row enlarged. The number of apical pits varies

from 0-2 within the tribe. Alsophiine ventral scutes range

from a minimum of 102-155 to a maximum of 160-230. Ven­

tral scutes are rounded in the majority of the genera and

angulate in only three forms. The anal plate may be sin­

gle or divided. The number of caudal scutes in alsophine

genera ranges from a minimum of 27 to a maximum of 214.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 226 d d d d d d d d d 34-55 54-119 85-130 72-88 27-60 43-94 60-94 100-162 d C 165-214 s s (1) d sd 45 d d d d s d d A d 145-180

160-230 102-155 114-156 112-186 140-200 153-192 r r V r r r or a 162-212 141-157 si a r r a r 0-2 1 0 0 157-206 0-2 0 0-2 1 166-177 2(?) 0 0 AP s s s s s s St k k 19 s 19 17-19 s 17-25 19.-21 19 15 11-19 DS PVR VRE r r r r19 17; o r % S r S Ey< LM r 17-23 L L MS MS M r 23-27 LM r M (mm) 700/140 297/105 670/250 720-340 1950/550 1020/150 1010/180 2000+ Body/Tail 1310/580 cyl cyl Body cyl cyl si el Genus Darlingtonia Farancia TABLE 9: TRIBE ALSOPHIINI - MORPHOLOGICAL INFORMATION Hydrodynastes cyl Helicops Hyp s irhynchus s Hyp cyl Alsophis Antillophis cyl Heterodon cyl Arrhyton Uromacer Uromacerina si Note: See Page 227 for abbreviations.

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ABBREVIATIONS FOR TABLES 9, 17, 22, 28, 34, 41, 45.

Body: cyl=cylindrical; si el=slender, elongate; sl=

slender; si comp=slightly compressed; comp=compressed;

dep=depressed.

Eye: L=large; M=medium; S=small; VS=very small; T=tiny;

r=round pupil; o=oval pupil; se=slightly elliptical pup­

il; v=vertical pupil; o fe=feebly oval pupil.

DS=Dorsal Scale Rows: PVR=paravertebral reductions;

NR=no reductions; VRE=vertebral row enlarged; IR=

irregularly reduced; 3R=third row reduced; 4R=fourth

row reduced; l-4R=first through fourth rows reduced.

s=smooth dorsal scales; k=keeled dorsal scales;

st=striated dorsal scales; fk=feebly keeled dorsal

scales.

AP=Apical Pits: +=apical pits present; I=indistinct

apical pits; NO=apical pits in neck region only.

V=Ventral Scutes; r=rounded ventral scutes; a=angulate

ventral scutes; si a=slightly angulate ventral scutes;

r/d=ventral scutes rounded and occasionally divided.

A= Anal Plate; d=divided anal plate; s=single anal

plate.

C=Caudal Scutes: d=divided caudal scutes; s=single

caudal scutes.

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Caudal scutes are always divided in the Alsophiini.

Head scutes follow the normal colubrid pattern! in

the Alsophiini with various exceptions as set forth in Tab­

le 10. There does not appear to be a general pattern of head scute variation within the tribe.

The Alsophiini share two generalized patterns in

maxillary dentition. Eight of eleven alsophiine genera

have a maxillary diastema followed by a pair of enlarged

but ungrooved rear teeth (Table 11). In Arrhyton, Alsophis,

Antillophis, Hydrodynastes, Uromacer t and Uromacerina the

rear teeth are enlarged. No information is available for

the size of the rear teeth of Darlingtonia. In Heterodon

the maxillary is short and the prediastemal teeth increase

in length posteriorly. In addition, Heterodon has fewer

prediastemal teeth than do other Alsophiini.

The remaining alsophiine genera, Farancia, Helicops,

and Hypsirhynchus have no diastema. Farancia1s maxillary

teeth are subequal in size, whereas in Hypsirhynchus the

teeth increase slightly in length posteriorly. The two

aquatic genera, Farancia and Helicops, have numerous maxi­

llary teeth, presumably an adaptation for seizing slippery

aquatic prey.

The Alsophiini show one final morphological pattern.

As set forth in Table 12, all have bilobed, semicapitate

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TABLE 10: TRIBE ALSOPHIINI - HEAD SCUTES

Genus Variation From Normal Colubrid Pattern

Alsophis -0 loreal in A. ater

Antillophis -temporals 1+1 or 1+2

Arrhyton -0-1 loreal

Darlingtonia -0 loreal; first pair of lower labials does

not meet in mid-ventral line

Farancia -0 or 1 preocular; nostril directed upward

in semidivided nasal; 2 or 1 internasals

Helicops -1 internasal; nostril directed upward

Heterodon -loreal missing or multiple; 1-14 azygous

scales; rostral turned up; temporals 2+3

or 4+5

Hydrodynastes -subocular present

Hyp s irhynchus -rostral forms acute angle with top of head;

0 loreal in some; prefrontals may be fused

Uromacer -sharply projecting rostral

Uromacerina -head scutes normal

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TABLE 11 : TRIBE ALSOPHIINI - MAXILLARY DENTITION

Genus Maxillary Dentition

Alsophis 12-21 + 2 postdiastemal teeth postdiastemal teeth strongly enlarged

Antillophis 16-21 + 2 postdiastemal teeth strongly enlarged

Arrhyton 17-19 + 2 maxillary short; postdiastemal teeth strong­ ly enlarged

Darlingtonia 17 + 2

Farancia 15-18 maxillary teeth subequal

Helicops 18-25 maxillary teeth increase in length posteriorly

Heterodon 6-11 + 2 maxillary short; postdiastemal teeth enlarged prediastemal teeth increase in length poster­ iorly

Hydrodynastes 12-17 + 2 postdiastemal teeth strongly enlarged

Hypsirhynchus 13-15 maxillary teeth increase slightly in length posteriorly

Uromacer 16-18 + 2 postdiastemal teeth very large

Uromacerina 23-25 + 2 postdiastemal teeth a little longer than prediastemal teeth

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TABLE 12: TRIBE ALSOPHIINI - HEMIPENES

Genus Shape Capitation Sulcus Ornamentation

Alsophis bilobed semicapitate forked spines calyces

Antillophis

Arrhyton*

Darlingtonia

Farancia " 11 " " "

Helicops

Heterodon

Hydrodynastes " " " " "

Hypsirhynchus

Uromacer

Uromacerina

*A. callilaemus, A. taeniatum, A. vittatum only.

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hemipenis with proximal spines, distal calyces, and

forked sulcus. The sulcus forks below the semicapitation.

Arrhyton is provisionally placed in the tribe Alsop­

hiini because four of its seven species have hemipenes of

the alsophiine kind. Three other species ( A. dolichrum,

A. funereus, and A polylepis ) have distinctly different

hemipenes. They are more properly allocated to Tribe

Philodryini. Because of the heterogenous nature of hemi­

penes within this genus, it is suggested that Arrhyton,

as recognised by Maglio (1960) is composite. Similarly,

Helicops has species which lack calyces. Because some

of its species do have calyces, Helicops is allocated to

the Alsophiini. Like Arrhyton, Helicops may be a composite

genus.

d. Geography

The geographic range of Tribe Alsophiini is centered

in Hispaniola. Five of the eleven alsophiine genera are

found here. Three are found northwest of this center, on

Cuba. Two genera are found in the southeastern United

States, two in Puerto Rico, and in the other more eastward

Lesser Antillean islands. The tribe's range stretches

through South America east of the Andes to Argentina. One

genus is found in the Galapagos and coastal Peru (Figure 204).

It is hypothesized that snakes ancestral to the Als­

ophiini originated in South America and dispersed from the

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FIGURE 204. Geographic Distribution of Tribe Alsophiini

CD = 1 genus

= 2 genera

= 3 genera

• = 5 genera

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure 204.

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northern South American mainland to the Lesser Antilles.

From the Lesser Antilles the tribe island-hopped to the

Greater Antilles and thence to Florida and the North Ameri­

can mainland. An alternate hypothesis would derive the

alsophiines from ancestors which arrived in North America

via the Bering Land Bridge. Subsequent southward migrations

would bring the alsophiines down into South America. This

latter hypothesis is rejected until electrophoretic or

immunological evidence substantiates that Xenodontinae is

a polyphyletic subfamily.

Table 13 shows the latitudinal distribution of Tribe

Alsophiini. Twenty-four species are found from 11 to 20°

North Latitide. From this latitudinal center the tribe

disperses north and south. Helicops is the most southern

genus. Heterodon is the most northern genus. From its

latitudinal distribution it can be seen that Tribe Alsoph­

iini is a northern group,

e. Discussion and Relationships

Dowling recognized 44 genera in his Tribe Alsophiini,

which was defined as a group of xenodontines with a semi-

capitate hemipenis (Dowling and Duellman, 1978). The

Alsophiini is here restricted and redefined as a xenodon­

tine tribe characterized by a bilobed, semicapitate hemi­

penis with proximal spines, distal calyces, and forked

sulcus. Present members of Tribe Alsophiini include

Alsophis, Antillophis, Arrhyton, Darlingtonia, Farancia,

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TABLE 13: TRIBE ALSOPHIINI -LATITUDINAL DISTRIBUTION

Darlingtonia Farancia Helicops Heterodon irhynchusHyps Uromacer Uromacerina Total Arrhyton Hydrodynastes Alsophis Antillophis f* H- rt C O- (0 01 rt 0 + a 1-1 -* O -* -C~ U l O 1 0 0 U l ■C- U l t o 0 0 a a a U l 0 0 0 0 0 0 1 t 1 1 1 -* M t - *N l 1-1 l - i 5 2 O O I I I I I I I O 1 —1 2 ! 0 0 I 0 0 —1 ( - * 1—1 CO O 0 0 0 1—■ N l C/5 O O 0 0 N l l- J M O C/5 U l 1—1 1—1 I— > I—> N 3 I— ‘ to Nl I Nl to 0 0 —1 U l 4 > 0 O 1 I 1 1 1 4 > M 1 -* C/1 C/5 U i OOO 0 i i i i or-'t'ot'orooocooi I I I I I IOt->N>OII I i I I I I O O' Ul O I I I I I I I I I O Nl N> N> Nl O I I I IlllilOl—>0111 I I I I 1 1 1 1 O 1 I 1 1 1 1 o ui ui to o IlllllO-OOIIt + 0 1 C/5 Ot-*tOUlUl00V£5UlOI I I Ol—■UlOvOI—iM.C'UlUiUlO

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Helicops , Heterodon. Hydrodynastes, Hypsirhynchus, Uro­

macer , and Uromacerina.

Tribe Alsophiini is the most generalized of three

northern tribes of xenodontines. It is hypothesized that

alsophines which colonized the Central American mainland

may have given rise to Tribe Dipsadini and Tribe Lepto-

deirini.

2. Tribe Diaphorolepini

Tribe Diaphorolepini is composed of ten genera with

92 species of xenodontine snakes which have a center of

distribution in southeastern Brazil.

DEFINITION: Tribe Diaphorolepini is defined by possession

of an entirely spinose, noncapitate hemipenis which has

a forked sulcus (Table 14).

a. Ecology

The scant ecological information (Table 15)demonstrates

that the tribe has specialized fossorial and terrestrial

members. Atractus, Cnersodromus. Enulius, and Elapomorphus

are fossorial. Enulius has maxillary specializations for

feeding on reptile eggs, while Elapomorphus is a semi-

fossorial Argentine snake which occupies inhabited ant

mounds and feeds on worms and insects. Inexplicably, its

bite is deadly to humans (Lema, 1970). Crisantophis is

a terrestrial snake which feeds omnicarnivorously, inclu­

ding fishes, tadpoles, frogs, toads, lizards, snakes, and

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TABLE 14: TRIBE DIAPHOROLEPINI - HEMIPENES

Genus Shape Capitation Sulcus Ornamentation

Atractus bilobed noncapitate forked spines only

Chersodromus " ” " " "

Crisantophis " " " spines + awns

Diaphorolepis " " " spines only

Elapomorphus

Enulius

Gomesophis slightly bilobed

Pseudotomodon bilobed " " ” "

Ptychophis bilobed, almost " " " " single Sordellina slightly bilobed

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TABLE 15: TRIBE DIAPHOROLEPINI - ECOLOGY

Genus Information

Atractus fossorial

Chersodromus fossorial, found in pine-oak forests

Crisantophis feeds on fishes, tadpoles, frogs, toads, lizards, snakes, and mammals

Diaphorolepis none

Elapomorphus semifossorial, nocturnal; feeds on worms, insects; symbiont in ant mounds

Enulius fossorial; feeds on reptile eggs

Gomesophis none

P s eudo t omo don none; may be viviparous

Ptychophis none

Sordellina feeds on frogs, caecilians; oviparous

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mammals in its diet. Sordellina feeds on frogs and caeci­

lians .

b. Morphology

Maxillary dentition in the Diaphorolepini shows a

trend toward opisthoglyphy (Table 16). Only three genera,

Atractus, Chersodromus, and Diaphorolepis have no diaste-

mata. In the first two genera the maxillary is short,

maxillary teeth decrease in size posteriorly, and there

are relatively few teeth. In Diaphorolepis there are

many (25) maxillary teeth and although there is no diast­

ema, the last two teeth are stouter than the others. Of

the seven genera which have diastemata, three have enlarg­

ed postdiastemal teeth, and four have rear fangs. Enul­

ius, which has unusual, relatively enormous, flattened

postdiastemal teeth, feeds on reptile eggs. Pseudotomo-

don and Crisantophis also have enormous and, in the lat­

ter instance, laterally compressed postdiastemal teeth

and fangs, respectively. They may also be egg-eating

snakes. Pseudotomodon1s diet is presently unknown, while

Crisantophis is an omnicarnivore.

Some morphological patterns are observed within the

Diaphorolepini. Total body length ranges from 308-1180

mm (Table i7). Tail length ranges from 68-160 mm. Eyes

vary from tiny to large. Seven genera have round pupils,

one genus has subelliptic pupils, and two genera have

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TABLE 16: TRIBE DIAPHOROLEPINI - MAXILLARY DENTITION

Genus Maxillary Dentition

Atractus 5-13; maxillary is short; maxillary teeth decrease in size posteriorly

Chersodromus 8-10; maxillary is short; maxillary teeth decrease i n size posteriorly

Crisantophis 13-14 + II; maxillary teeth increase in length posteriorly; fangs laterally compres­ sed and grooved.

Diaphorolepis 25 maxillary teeth; last two teeth are stout­ er than the others; no diastema

Elapomorphus 4-5 + II; maxillary is short

Enulius 3-4 + 2; maxillary teeth increase in size posteriorly; postdiastemal teeth are flatten­ ed and relatively enormous

Gomesophis 13-15 + II; maxillary teeth increase in size posteriorly

Pseudotomodon 8+2; postdiastemal teeth are huge

Ptychophis 18 + II

Sordellina 9+2; maxilla is short; postdiastemal teeth are enlarged

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vertical pupils. The range of dorsal scale rows is rem­

arkably consistent amongst the Diaphorolepini. The tribe

is characterized by 13-21 dorsal scale rows, with most

genera having 15 to 17 rows. Dorsal scales are generally

smooth, although two genera have striated, keeled scales;

and one genus has representatives with either keeled or

smooth scales. Most diaphorolepines have no apical pits,

although one or two apical pits are present in three gen­

era. Ventral scutes range from a minimum of 127-130 to a

maximum of 193-197. Ventral scutes are rounded in five

of the 11 diaphorolepine genera. Shape of ventral scutes

is not recorded for the others. Caudal scutes range

from a minimum of 21-45 to a maximum of 88-138. Anal

plates are divided in six genera and unreported in four

genera.

Head scutes in the Diaphorolepini (Table 18) show

little variation from the normal colubrid pattern, altho­

ugh the nasal region is often modified. Four genera have

a single or semidivided nasal. One genus has a prominent

nasal valve, and a final genus has a concave, posterior

nasal plate. In three genera there is one prefrontal,

while one genus may have either 1 or 2 prefrontals.

The members of Atractus which have spinose noncaly-

culate hemipenes ( A. elaps and A. trilineatus groups)

are included in the Diaphorolepini. The four member

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 242 36-43 d 71-89 -- 98-138 -- 21-45 d 82-105 d 41 43-53 d 200 127-138 173-183 V r 193-197 176-240 127-147 153 148-150 r r

AP + s s 0 st 0 s s 0 st k - - s s 0 s s 1 k

15-17 13-17 s 1(2) 129-216 17 17 NR NR S S 15-17 S S 19-19-17 r , r , se T,M r v r k S se L 21-19-17 s 0 r T,S 15 s 0 r v M

(mm) 308/68 828/160 684 340/140 cyl cyl s i Body Body/Tail Eye PS cyl 1180/120 cyl 528/87 NOTE: See Table 9 for key to abbreviations Genus Chersodromus TABLE 17: TRIBE DIAPHOROLEPINI - MORPHOLOGICAL INFORMATION Sordellina Diaphorolepis Crisantophis Atractus Enulius Elapomorphus Ptychophis Gomesophis Pseudotomodon

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TABLE 18: TRIBE DIAPHOROLEPINI - HEAD SCUTES

Genus Variation From Normal Colubrid Pattern

Atractus loreal may be absent; preocular may be

absent; no subocular; nasal with prom­

inent valve.

Chersodromus 0 preocular; 1 prenasal; posterior nasal

concave; 1 prefrontal; 0 anterior temp­

oral.

Crisantophis normal head scutes.

Diaphorolepis ■ 1 prefrontal; 9 supralabials.

Elapomorphus fused prefomtals in some; 2 prefrontals

in others; in some rostral separates

internasals.

Enulius -0 preoculars •

Gomesophis -normal head scutes

Pseudotomodor. -normal head scutes

Ptychophis -normal head scutes

Sordellina -normal head scutes

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Atractus badius group is problematic because it has a

flounced hemipenis. The non-Ecuadorian snakes not grouped

in Savage's (1960) generic revision are also tentatively

included in this tribe until a thorough investigation of

their hemipenes makes their tribal allocation more certain.

As it is presently recognized, Atractus, as suggested by

the heterogenous nature of hemipenes within the genus,

may be a composite.

Two species of Arrhyton also can be placed tentativ­

ely into the Diaphorolepini because their unusual hemi­

penes are fully spinose. In Arrhyton polylepis, the sin­

gle, spinose hemipenis has a slightly bifurcate apical

crown, while in Arrhvton funereus. a distinct apical prom­

inence rises above the apex. Although details of its

habits are unknown, Arrhyton matches the morphological

trends observed in the Diaphorolepini. Arrhyton. as def-

fined by Maglio (1960) may also be a composite genus,

c . Geography

The Diaphorolepini range from a center of concen­

tration in southern South America through northern South

America east of the Andes to Northern Venezuela, and Colo­

mbia (Figure 205). They range northward from Colombia through

Panama, along the Pacific coast of Costa Rica and Honduras

to the northern Caribbean coast of Nicaragua, as well as

along the Pacific coast of Guatemala to the Pacific coast

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FIGURE 205: Geographic Distribution of Tribe Diaphorolepini

= 1 genus = 2 genera = = 3 genera • = 4 genera

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of southern Mexico as far north as Michoacan. Two iso­

lated diaphorolepines exist in Mexico: one at the south­

ern edge of the Mexican plateau, the other in Nayarit.

d. Discussion and Relationships

The latitudinal distribution of the Diaphorolepini,

with its preponderance of species in the southern hemisphere

indicates the southern affinities of this tribe (Table 19).

Because the concentration of diaphorolepine genera is in

southern South America, it is assumed that the tribe orig­

inated here and moved northward in post-Pliocene times.

The spinose hemipenis characteristic of the tribe may indi­

cate a relationship to the Old World subfamily Lycodont-

inae which has chevrons of spines and a few calyces on a

bilobed hemipenis.

The Hydropsini was defined (Dowling and Duellman,

1978) as a tribe of six xenodontine genera with spinose,

noncalyculate hemipenes. This definition, as well as

three of Dowling's genera are retained. Hydrops, however,

has been transferred to the Philodryini because it pos­

sesses a few calyces on its spinose, noncapitate hemipenis.

The substitute tribal name, Diaphorolepini, therefore is

proposed for this group.

Tribe Diaphorolepini as here defined includes Atractus,

Chersodromus, Crisantophis, Diaphorolepis, Elapomorphus,

Enulius, Gomesophis, Pseudotomodon, Ptychophis, and Sor-

dellina.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 7 3 CD ■o o-5 Q. C o O.CD

■ o CD AL 1: RB DAHRLPN - AIUIA DISTRIBUTION - LATITUDINAL DIAPHOROLEPINI TRIBE 19: TABLE C/) Cn 4> CO to I—1 i-* to CO Cn f (f) h-1 t—• 1-* I—* h-* o O i-* I—1 »-» i—1 (D o o o o o o o o O o o o rt + 1 1 1 1 1 1 1 1 1 1 + H- C/5 Cn J> co to I-* to CO -C- Cn a rt O O o o o O o o O O £ o o o o 0 o o o O o Cc o 1/1 C/5 c/5 tZ) C/5 a a a a a (0 o ■O

u> o 1-* CO O' vO cn 00 o till Atractus

i 1111o1-*1—1 O 1 1 1Chersodromus 3. CD i 1111oI—* o lilt Crisantophis

■oCD -5 o i 11oI—*too 1till Q. Diaphorolepis C a o i- * CO 00O'o 111t i ll Elapomorphus ■o o t 1 1 1o to1—‘ I—*oil! Enulius

CD Q. oh -* V—> o1111l i l t Gomesophis

t-» 1—* 1—*o 1 1 1 1 1 1 1 1 Ps eudo tomodon ■o CD

C/) o o to o 1 1 1 1 1 1 1 1 Ptychophis C/)

o o I—1I—* o 1 1 1 1 1 1 1 Sordellina

1—>to to CO 1—1 to Cn ON CO o VO h-* to o o o o Total 248

3. Tribe Dipsadini

Tribe Dipsadini includes thirteen xenodontine genera

with 184 species ot snakes which have a center of distri­

bution in Central America.

DEFINITION: Tribe Dipsadini is defined by possession of

a fully capitate hemipenis with proximal spines and a

forked sulcus (Table 20).

a. Ecology

The majority of dipsadine genera are adapted for

obtaining a diet of slugs and snails (Table 21). Although

members of four genera feed on vertebrates, such as fish­

es, salamanders, frogs, tadpoles, lizards, and snakes

(including eggs); and dietary information is unavailable

for three genera, seven dipsadine genera are known to

consume a largely or completely molluscan diet. Four

feed exclusively on molluscs, while two others supplement

the molluscan diet with soft bodied insect larvae and with

caecilians. A third consumes a wide variety of verte­

brates in addition to molluscs.

The Dipsadini inhabit humid cloud, mesic hill, and

humid montane forests. They are, in general, nocturnal

snakes, although two genera are diurnal. Reflecting their

nocturnal habit, four genera have vertical pupils (Table

22). two have oval or feebly elliptical pupils. Of the

five dipsadine genera with round pupils, tv;o are aquatic*

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TABLE 20; TRIBE DIPSADINI - HEMIPENES

Genus Shape Capitation Sulcus Ornamentation

Adelphicos+ S - SLB Capitate ? Calyces Spines

Coniophanes* S - SLB Capitate Forked Calyces Spines

Cryophis S Capitate Forked Calyces Spines

Dipsas SLB Capitate Forked Calyces Spines

Geophis S - B Capitate Forked Calyces Spines Semicapitate Noncapitate

Ninia S Capitate Forked Calyces Spines

Pliocercus B Capitate Forked Calyces Spines

Rhadinaea S - SLB Capitate Forked Calyces Spines

Sibon SLB Capitate Forked Calyces Spines

Sibynomorphus S Capitate Forked Calyces Spines

Tretanorhinus S - SLB Capitate Forked Calyces Spines

Trimetopon S - SLB Capitate Forked Calyces Spines

Tropidodipsas S Capitate Forked Calyces Spines

*Coniophanes bipunctatus, C. brevifrons, C. dromiciformis, C. fissidens, C.lateritius, C. picevittis, and C. quin- quevittatus only.

+ Smith's (1940) erroneous description of Adelphicos' hemipenis records a simple sulcus, flounces, spines and no calyces. Because the nature of the sulcus has yet to be determined (it was unfindable in the only specimen available), Adelphicos is allocated to Tribe Dipsadini. If it has a simple sulcus, it belongs to Tribe Leptodeir- ini. Adelphicos1 hemipenis has a capitation of calyces.

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TABLE 21 : TRIBE DIPSADINI - ECOLOGY

Genus Information

Adelphicos none

Coniophanes semiaquatic; diurnal; feeds on snails, slugs eels, frogs, lizards, and snakes.

Cryophis arboreal; nocturnal; feeds on snails and slugs.

Dipsas arboreal; nocturnal; feeds on snails, slugs, and soft-bodied insect larvae

Geophis none

Ninia terrestrial, secretive; crepuscular; feeds on snails, slugs, caecilians, beetles (?).

Pliocercus terrestrial; nocturnal; feeds on salamanders and on frogs (captivity).

Rhadinaea terrestrial or semifossorial; diurnal; feeds on salamanders, frogs (including eggs), lizards, and snakes (including eggs).

Sib on arboreal; nocturnal; feeds on snails and slugs

Sibynomorphus arboreal; nocturnal; feeds on snails and slugs

Tretanorhinus nocturnal; aquatic, possibly marine; feeds on fishes, frogs, and tadpoles

Trimetopon fossorial; probably feeds on invertebrates

Tropidodipsas arboreal, terrestrial; nocturnal; feeds on snails and slugs.

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two are fossorial, and one is terrestrial/diurnal,

b. Morphology

Table 22 summarizes dipsadine morphological inform­

ation. Body shape of the Dipsadini ranges from cylindrical

to slightly or strongly compressed. Total lengths range

from 300 to 900 mm. Tail lengths range from 77 to 260 mm.

Number of dorsal scale rows varies from 11 to 25. Of the

eight dipsadine genera for which there is information on

scale row reductions, four show no scale row reductions,

two are rarely or only irregularly reduced, while four

have reductions through loss of the paravertebral rows.

Nine genera have smooth dorsal scales, while three have

keeled, striated dorsal scales, and one has keeled or

smooth scales. In two genera the vertebral scale row

is enlarged. The number of ventral scutes ranges from

a minimum of 110-197 to a maximum of 162-200. Ventral

scutes are generally rounded, although two genera have

members which have angulate ventral scutes. The anal

plate is single in seven genera, and divided in six gen­

era. The number of caudal scutes ranges from a minimum

of 19-66 to a maximum of 85-127. Caudal scutes are div­

ided.

Dipsadinine head scutes (Table 23) follow the normal

colubrid pattern except 0-4 pre- and 0-2 postoculars may

be present and supralabials vary from 5 to 11.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 252 — ■ — d d d d d d d 131 22-49 62-115 19-66 82-145 C 37-101 85-127 31-137 41-126 d 37-85 d 50-85 d s s d s d d s r s r r r r s r d r/d — r d

131-177 136-201 120-143 110-197 136-201 162-200 115-185 less than 200 111-174 186 121-148 VA + 0 AP 0 0 0 0, 0, 0 0 0 0 0 s s s s k k,st s 0 s VRE St k 15 11-19 15-17 17-21 17-25 19,21 15,17,s . IR 21 17 s 13,17 15 17-21 VRE DS PVR k PVR PVR NR PVR NR fe r o, r V V r V r o S S Eye L L T r M r S M L M M (mm) 400/-- 650/131 525/195 400 415/125 900/-- 560/260 si Body Body/Tailcyl comp cyl cyl cyl slcomp comp cyl cyl 685/160 Dipsas Coniophanes TABLE 22; TRIBE DIPSADINIGenus MORPHOLOGICAL- INFORMATION Cryophis Geophis Sibynomorphus Adelphicos Sibon Ninia Pliocercus Rhadinaea cyl Tretanorhinus

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. without prohibited reproduction Further owner. copyright the of permission with Reproduced

TABLE 22 (Con' 3 73 73 ovo vo o o m CO 3 7 i i

cn cn 253 254

TABLE 23: TRIBE DIPSADINI - HEAD SCUTES

Genus Variation From Normal Colubrid Pattern

Adelphicos 0 pre-, 2 postoculars; temporals 1+1; small rostral; anterior genial enlarged.

Coniophanes Head scutes normal except that 9 supra- labials may be present.

Cryophis concave nasal; third upper labial extends to loreal.

Dipsas 0 preocular; temporals irregular; 7-11 supralabials, none in contact with post­ ocular.

Geophis ■head scutes variable.

Ninia ■usually 0 preocular; posterior nasal con­ cave; 5-8 supralabials.

Pliocercis ■head scutes normal.

Rhadinaea -1-3 pre-, 2 postoculars.

Sibon -labial beneath primary temporal greatly enlarged and in contact with postocular, primary and secondary temporals.

Sibynomorphus -head scutes normal.

Tretanorhinus -1-3 prefrontals; nostril directed upward.

Trimetopon -1 prefrontal fused with other head scutes; 1 or 2 postoculars.

Tropidodipsas -0-4 pre, 2(1) postoculars; 1+2 temporals; divided nasal; 6-7 supra- , and 6-9 infralabials.

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In the single aquatic dipsadine genus the nostrils are

directed upward. One genus has the labial below the

primary temporal greatly enlarged and in contact with the

postoculars, primary, and secondary temporals. In Geo-

phis and other burrowing snakes the head scutes are

variable.

Maxillary dentition of the Dipsadini (Table 24) shows

two general trends: adaptation for prying molluscs from

their shells and adaptations which may aid in seizing ter­

restrial or aquatic prey. Mollusc-feeders have the anter­

ior maxillary teeth longer than the posterior ones, as

well as other modifications for seizing their slippery

prey. In Cryophis and Tropidodipsas, for example, the ant­

erior maxillary teeth are longest. In Dipsas a second

dental variation for snail eating is observed. Dipsas1

subequal-sized maxillary teeth are directed inward and

increase in length posteriorly. In Sibynomorphus the

maxillary teeth are also directed inward, but, in addition,

the anterior teeth have been lost. This edentate cond­

ition may enable Sibynomorphus to use its maxillary as a

wedge for removing a snail's operculum, or as a lever for

prying it from its shell.

Tretanorhinus, an aquatic dipsadine known to feed on

fishes, frogs, and tadpoles, has numerous (27-30) subequal-

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TABLE 24: TRIBE DIPSADINI - MAXILLARY DENTITION

Genus Maxillary Dentition

Adelphicos 9-10; maxillary teeth decrease in size posteriorly, largest are near middle of tooth row.

Coniophanes 8-15 + II; prediastemal teeth are subequal in size; fangs moderately enlarged.

Cryophis 19-22 + 2; prediastemal teeth decrease posteriorly, rear teeth are slender, enlarged.

Dipsas 12+; maxillary teeth directed inwards, subequal-sized, increase in length post­ eriorly.

Geophis 6-17; first and last teeth are shorter than the others.

Ninia 15-18; maxillary teeth small, subequal­ sized.

Pliocercus 18+2; rear teeth enlarged

Rhadinaea 10-24 + 2; rear teeth enlarged, rarely grooved.

Sibon 15; anterior teeth are longest; remainder are subequal-sized.

Sibynomorphus anterior maxillary edentate; maxillary tooth edge directed inwards.

Tretanorhinus 27-30; maxillary teeth subequal-sized.

Trimetopon less than 14 maxillary teeth; increase in length to the last; short maxilla

Tropidodipsas 8-10 or 12-18; maxillary teeth decrease in size posteriorly.

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sized maxillary teeth which may aid it in seizing slippery

aquatic prey. Two of the three dipsadines with a max­

illary diastema feed on terrestrial vertebrates in addi­

tion to snails and slugs. Their enlarged rear teeth (one

genus has fangs) may aid them in subduing their vertebrate

prey.

Adelphicos, Geophis, and Trimetopon have relatively

few maxillary teeth. The teeth are reduced in size post­

eriorly (Geophis, Adelphicos) or on a short maxilla

(Trimetopon). Ninia, which has a moderate number of small,

subequal teeth, may also be a member of this group of dip­

sadines with reductions in maxillary dentition.

The dipsadines share one further morphological

distinction (Table 20). They are the only xenodontine

tribe which has a fully capitate hemipenis with a forked

sulcus spermaticus. The shape of the hemipenis is usu­

ally single, although some dipsadine hemipenes are slight­

ly bilobed at the apex. The capitation is primarily

composed of calyces, and proximal spines or hooks are

usually present. The capitation may be restricted to

the apex of the hemipenis, or it may include as much as

two-thirds of the body of the hemipenis. Because some

genera ( e.g. Geophis, Rhadinaea ) have members with

either single or a slightly bilobed hemipenis, it is

logical to assume that the dipsadines originated from

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a now-extinct ancestral form which had a bilobed, perhaps

semicapitate hemipenis.

c . Geography

The geographic range of the Dipsadini (Figure 206)

extends from a tribal concentration in Middle America

northward to Texas on the Caribbean coast and to Sinaloa

on the Pacific coast. One aquatic genus (Tretanorhinus)

has colonized Cuba and two nearby islands. The tribe

extends southward to include all of South America north

of about 35° S latitude. Subsidiary centers of tribal

concentration are observed in south-central Brazil and

in western Colombia, Ecuador, and Peru.

That this tribe originated in Middle America and has

subsequently radiated southward to colonize South Amer­

ica is shown by the dense concentration of genera in

Caribbean Nicaragua, Costa Rica, and Panama.

d. Discussion and Relationships

The latitudinal distribution of Tribe Dipsadini

(Table 25) shows that most species are found between

0° and 20° North Latitude. Fewer numbers of species

are found south of the equator. Tribe Dipsadini, there­

fore, is a northern tribe of xenodontines, along with

Tribes Alsophiini and Leptodeirini. It is suggested

that the Dipsadini originated from alsophine ancestors

which reached the Middle American mainland in pre-Pliocene

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FIGURE 206: Geographic Distribution of Tribe Dipsadini

= 1 genus = 2 genera = = 3-6 genera = 7-10 genera

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. O' o

TABLE 25: TRIBE DIPSADINI - LATITUDINAL DISTRIBUTION Coniophanes Cryophis Dipsas Adelphicos Geophis Sibon Sibonymorphus Ninia Pliocercus Rhadinaea Tre t anorh inus anorh t Tre Tropidodipsas Trimetopon Total (D r t H* C f rt 1 + Z Cn 1 0 CC 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Z © cn 1 1 1 I 1 1 1 1 1 1 1 1 1 1 1 1 —1 o—1 o I—1 I—1 O 1 1 O O O 1 O O 1 1 O O O 1 1 z t - 1 t— O CO 1 o o o o o o 1 I—* to to t—1 o CO Cn CO to "J CO o o Z ho 1— CO 4 > o 1 1 1 1 to I—* to o o O' O' 0 0 I—1 -o Cn cn to CO o VO h - Z (-* ho o

1 1 o 4> 1— Cn "J O' o o CO o CO t-J CO CO O' Cn z t—1 O O 1 o o o 1 1 1 1 to to ho 1—* 1—* c n o o h -1 o CO J— Cn o o o o o O o 1 1 1 1 1 H-* -S' o o o CO o 0 0 t o t o 1—* ho h-> o

o o 1 1 1 1 t 1 1 1 1—* CO O ' CO CO to h-> o 1 o 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 to O' o i— O •C~ CO o o 1 1 1 1 1 1 1 1 1 1 1 1 1 o O o to to I—* o 4 > CO ho 1—* Cn o o + H-* to c n

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 261

times. The tribe moved south after the isthmian connection

was established in the Pliocene. At the northwestern

extension of its range, Tribe Dipsadini gave rise to the

ancestors of Tribe Leptodeirini. The leptodeirine hemi­

penis is identical with that of the dipsadinines, except

for its simple sulcus,

e . Summary The Dipsadini, as here recognized, is a tribe of

xenodontine snakes which originated in Mexico-Central

America from alsophine-like ancestors. The tribe is

distinguished by its forked sulcus on a single or sli­

ghtly bilobed, fully capitate hemipenis. Members of

the tribe are variously adapted for feeding on snails

and slugs. The genera here allocated to Tribe Dipsadini

include Adelphicos, Coniophanes, Cryophis. Dipsas.

Geophis, N inia, Pliocercus, Rhadinaea, Sibon. Sibyno­

morphus , Tretanorhinus, Trimetopon. and Tropidodipsas.

Two species of Coniophanes (C. imperialis and C. biser-

ialis) which have a flounced hemipenis are not included

in this tribal allocation. Dowling and Duellman (1978)

recognized twenty-four additional genera as dipsadines.

These genera are allocated to other tribes. Hydromorphus,

a genus whose hemipenis is reported (Wood, 1939) to res­

emble that of Tretanorhinus, may be a dipsadine. Until

this observation is confirmed, tribal allocation of

Hydromorphus is deferred.

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A. Tribe Leptodeirini

Tribe Leptodeirini is a small tribe composed of four

genera with 21 species of xenodontine snakes, character­

ized by a unique hemipenis which is single and fully cap­

itate with a simple sulcus (Table 26).

DEFINITION: Tribe Leptodeirini is defined by possession

of a fully capitate, single or bilobed hemipenis with a

simple sulcus.

a. Ecology Although ecological information is lacking for Eri-

diphas, the habits of the other Leptodeirini are better

known (Table 27). All are nocturnal or crepuscular. Species

of Leptodeira, the most widely distributed and varied

genus, are terrestrial, arboreal, semiaquatic, and secre­

tive. Hypsiglena is nocturnal, while Imantodes is noct­

urnal or crepuscular, and shows arboreal specializations.

All three genera feed on cold-blooded prey such as lizards

and frogs. Leptodeira also includes frog eggs and toads

in its diet. Both Hypsiglena and Leptodeira are oviparous,

and the mode of reproduction of the others is unknown.

b. Morpholoev

Morphological similarities also characterize this tribe (Table 28). Three genera have a large eye with a verti­

cal pupil, whereas Hypsiglena has a very small eye. All

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TABLE 26: TRIBE LEPTODEIRINI - HEMIPENES

Genus Shape Capitation Sulcus Ornamentation

Eridiphas single capitate simple calyces spines

Hypsiglena single, capitate simple calyces spines bilobed

Imantodes single capitate simple calyces spines

Leptodeira single capitate simple calyces spines

TABLE 27 TRIBE LEPTODEIRINI - ECOLOGY

Genus Ecological Information

Eridiphas -none

Hypsiglena -nocturnal; feeds on lizards; oviparous

Imantodes -arboreal; nocturnal or crepuscular; feeds on frogs and lizards.

Leptodeira -terrestrial, arboreal, semiaquatic; nocturnal; secretive; feeds on frogs (including eggs),

toads, lizards; oviparous.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 264 36-71 36-71 d 109-175 109-175 d 54-107 54-107 d C A - - d - d 55-68 d r r s/d r r d 154-204 184-190 V 150-211 1 1 2 0 214-267 AP s s s 23 17-23 s 17+15+13 17-25 VRE PVR DS V V V V VS L L L Eye

(mm) 700/-- 424/70 Body/Tail 1100/340 1000/200 cyl Body cyl si comp cyl TABLE 28: TRIBE LEPTODEIRINI - MORPHOLOGICAL INFORMATION Imantodes Eridiphas Hypsiglena Genus Leptodeira Note: Note: Table See 9 for abbreviations.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 265

Leptodeirini have smooth scales. The number of dorsal

scale rows ranges from 13-25. In Leptodeira the dorsal

rows reduce through loss of the paravertebral rows.

Total length ranges from 700 mm to one meter. Tail len­

gth ranges from 70-340 mm. Number of apical pits varies

from 0 to 2. Number of ventral scutes ranges from 150-

211. The anal plate is usually divided, although it may

be single in Imantodes. Caudal scutes range from a min­

imum of 36-71 to a maximum of 109-175. In Imantodes the

vertebral scale row is enlarged, an adaptation for arb­

oreal existence. Tribe Leptodeirini is characterized by

modification of the pre- and postocular scales (Table 29).

Three genera have 1-4 preoculars and 1-3 postoculars.

The temporal region is also modified.

All members of the tribe have a diastema and enlarged

rear teeth (Table 30). In Hypsiglena the postdiastemal

teeth are fang-like, while in Eridiphas the maxillary

teeth increase in size posteriorly. Imantodes1 maxillary

teeth are subequal-sized, while its anterior mandibular

teeth are longer, a modification which allows this arb­

oreal snake a more secure grasp on prey. In Leptodeira

the prediastemal teeth are subequal, while the fangs are

large and grooved. Thus, there may be a trend towards

loss of anterior maxillary teeth, enlargement of rear teeth,

and development of opisthoglyph dentition amongst the

Leptodeirini.

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TABLE 29: TRIBE LEPTODEIRINI - HEAD SCUTES

Genus Variation From Normal Colubrid Pattern

Eridiphas -rostral twice as broad as deep.

Hypsiglena -2-3 pre-, and 1-3 postoculars; temporals 1+2+3; 2 nasals.

Imantodes - 1-3 preoculars.

Leptodeira - 1-4 preoculars; temporals 1+2+3; post­ erior nasal concave; infralabials 8-12(10).

TABLE 30: TRIBE LEPTODEIRINI - MAXILLARY DENTITION

Genus Maxillary Dentition

Eridiphas 12+2; maxillary teeth increase in length posteriorly.

Hypsiglena 7-14+2; prediastemal teeth subequal-sized; postdiastemal teeth fang-like.

Imantodes 12-18+2; maxillary teeth subequal in size; anterior mandibular teeth are longest.

Leptodeira 8-11+II; maxillary teeth subequal-sized; rear fangs are large.

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c. Geography and Relationships

The distribution of Tribe Leptodeirini is shown in

Figure 207. From a center of distribution on the northern

Pacific coast of Mexico, the Leptodeirini range north to

the states of Washington and Kansas. The tribe's range

extends south to central Argentina. Two genera are found

on the southern part of the Baja California peninsula.

The latitudinal distribution of Tribe Leptodeirini (Table

31) shows a c o n c e n tra tio n o f sp ecies from 20° to 30°

North Latitude. The Leptodeirini, therefore, is the most

northern of the northern group of xenodontine tribes.

Because of the distinctive fully capitate hemipenis with

a simple sulcus, it is hypothesized that the tribe origi­ nated from a dipsadine ancestor. The Dipsadini are

characterized by a fully capitate hemipenis with a forked

sulcus.

d . Summary

Tribe Leptodeirini as here recognized includes Eri-

diphas, Hypsiglena, Imantodes t and Leptodeira. The

tribe most likely originated from dipsadine ancestors

in northern Pacific Mexico and extended its range to

include South America in post-Pliocene times.

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Figure 207: Geographic Distribution of Tribe Leptodeirini

0 = 1 genus = 2 genera • = 3 genera

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TABLE 31: TRIBE LEPTODEIRINI - LATITUDINAL DISTRIBUTION

CO cO CO c CO Vc CO <0 CO •H X i— i T 3 (0 a 00 o *T3 •rH •H 4-) O rH TJ CO G 4 J CO •i-l a cO a 4 J U E <0 O Latitude W X M ►J H

51°+N - 0 - - 0

41°-50°N - 1 - - 1 31°-40°N 0 1 0 0 1 21°-30°N 1 2 2 6 11 11°-20°N 0 2 4 9 15 0°-10°N - 0 4 2 6

0°-10°S - - 2 2 4

11°-20°S - - 2 2 4

21°-30°S -- 1 1 2

31°-40°S - - 1 0 1 41°-50°S -- 0 - 0

51°+S - _ _ _ 0

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5. Tribe Philodryini

Tribe Philodryini is composed of 16 genera with 61

species of xenodontine snakes which have a distributional

center in southern South America.

DEFINITION: Tribe Philodryini is characterized by pos­

session of a bilobed or single, noncapitate hemipenis

with a forked sulcus, proximal spines, and distal calyces

(Table 32) .

a. Ecology

Although ecological information is lacking for six

philodryine genera, the other members of the tribe are

mostly terrestrial, with a few known to be fossorial,

arboreal, or aquatic. Three genera feed on invertebrates,

while five feed omnicarnivorously, including salamanders,

frogs, toads, snakes, lizards, rodents, and birds in

their diet (Table 33).

b. Morphology

Body shape of the Philodryini varies from cylindrical

to slightly compressed, with one member, Calamodontophis,

having a stout body. Total lengths range from a maximum

of 330-1050 mm. Philodryas and Xenopholis are the long­

est and shortest members of the tribe, respectively.

Tail lengths range from a maximum of 310 mm for Philodryas,

to a minimum of 45 mm for Apostolepis. The eye varies

from tiny in Hydrops, an aquatic genus, to large in Man-

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TABLE 32: TRIBE PHILODRYINI - HEMIPENES

Genus Shape Capitation Sulcus Ornamentation

Amastridium single noncapitate forked spines calyces

Apostolepis single noncapitate forked spines calyces

Calamodontophis no description available

Carphophis slightly noncapitate forked spines calyces bilobed

Contia slightly noncapitate forked spines calyces bilobed

Diadophis bilobed noncapitate forked spines calyces

Hydrops bilobed noncapitate forked spines calyces

Manolepis bilobed noncapitate forked spines calyces

Nothopsis single noncapitate forked spines calyces

Philodryas bilobed noncapitate forked spines calyces

Pseudablabes bilobed noncapitate forked spines calyces

Synophis distally noncapitate forked spines calyces bilobed

Tachymenis bilobed noncapitate forked spines calyces

Thamnodynastes single noncapitate forked spines calyces

Tomodon bilobed noncapitate forked spines calyces

Xenopholis single, noncapitate forked spines calyces bilobed

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TABLE 33: TRIBE PHILODRYINI - ECOLOGY

Genus Ecological Information

Amastridium terrestrial, secretive

Apostolepis fossorial; feeds on worms

Calamodontophis none

Carphophis fossorial; feeds on worms, snails, slugs, and soft-bodied insects

Contia terrestrial; nocturnal; feeds on snails and slugs

Diadophis terrestrial; feeds on worms, insects, frogs, toads, salamanders, lizards, and snakes

Hydrops aquatic; nocturnal; feeds on fishes and frogs

Manolepis none

Nothopsis terrestrial; nocturnal; feeds on salamanders

Philodryas arboreal; diurnal; feeds on frogs, lizards, snakes, and birds

Pseudablabes none

Synophis none

Tachymenis terrestrial, semiarboreal; feeds on frogs,

toads, salamanders, lizards, and rodents

Thamnodynastes none; viviparous

Tomodon arboreal, feeds on lizards and small rod­ ents ovoviparous

Xenopholis none

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 273 — si, si, scyl cyl, el cyl cyl cyl cyl Body comp, si cyl cyl - d d d d cyl, d comp d d d d 37-69 d 32 d stout 21-52 d 27-57 40-76 81-112 51-64 23-28 J s s d 69-83 s d 68-86 a d d d d 30-77 d AC - - - r r r a r r d r d r d 82-140 ------160-265 171-186 157-231 128-138 134-169 149-162 a s 147-186 135 V 1 0 148-191 1 0 1 0 0 + + NO 119-170 AP s s St s s s 1,2 s s s 1(0) 126-239 s s s 0 112-146 k k k k 19, 19, 17 15, 15, 17 3R 17 15 17 19 4R 21, 19 s 15 24-30 13 D r r r 15 V V V S -- S S r TM T r M M r 13 L L M r Eye M r M r 13-19 (mm) 380/85 765/230 724/ — 724/ 355/50 360/ — 360/ 530/90 780/110 433 620/45 483/ — 483/ 550/140 Body/Tail 1050/310 Synophis Tachymenis Pseudablabes Philodryas Diadophis— 749/ Genus Hydrops Carphophis Contia Calamodontophis Nothopsis TABLE 34; TRIBE PHILODRYINI - MORPHOLOGICAL INFORMATION Apostolepis Manolepis Amastridium

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. without prohibited reproduction Further owner. copyright the of permission with Reproduced

TABLE 34 (Cont, l - r t—1 rH 0 0 co pH VO 0 * 3 7 CO r < 0 " f—i O - r H Ov T3 . n VO o oo O X X + + H P o ' > P P £ X O CO CO CD CO CO — 1 1 s * k r < l—1 rH i—4 i-H r < CM ) T t vO 1—4 i—1 CO ov o - r - f OCO VO pH i-H m T3 o S H H o CO P X s O o C o 1 • 1 | H !S rH rH CM oo i—i r < O CM oo Ov ) T CO - pci I-" - r —4 r— m CO ,C •i-4 CO o m X P u CO P > CO X G O Pu O co CD i 1 X X <4-1 •i-4 X v O H • O W W 2 H H P G P CO P CO o CO o CO Cl) CD CD 274 275

olepis, Philodryas, and Thamnodynastes. Pupils are round

in ten genera, vertical or round in one genus, and vert­

ical in four genera. Dorsal scale rows range from 13 to

30, with all but two members having 13-19 dorsal scale

rows. Synophis has 21 scale rows, while the number of

Nothopsis' dorsal scale rows ranges from 24 to 30. Dorsal

scales are reduced in Hydrops through the loss of the

third row, and through loss of the seventh row in Nothop­

sis . Dorsal scales are smooth in eleven genera, keeled

in Nothopsis, and smooth or keeled in four genera. In

Amastridium the otherwise smooth scales are keeled in

the posterior rows. In Synophis the smooth or keeled

scales are striated in the vertebral row. Six genera have

no apical pits; four genera are described as having "pits

present"; three genera have one apical pit; and two gen­

era have 0-2 apical pits. Number of ventral scutes var­

ies from a minimum of 112-146 in Carphophis to a maximum

of 160-265 in Apostolepis. Ventral scutes are rounded in

the majority of phylodryine genera. The anal plate is

divided in 10 genera, single or divided in three genera,

and single in three genera. Caudal scutes range from a

minimum of 21-52 in Apostolepis to a maximum of 82-140

in Philodryas. Caudal scutes are divided in 14 genera,

single or divided in one genus, or single in one genus.

Ten philodryine genera have a maxillary diastema

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 276

and enlarged rear fangs (Table 35). One genus has a dia­

stema and normal-sized rear teeth. Four genera have no

diastema. In eight of the genera with rear fangs there

is a moderate number of prediastemal teeth and the max­

illary is of normal size. In contrast, two genera have

a short maxillary and few prediastemal teeth. In these

genera the rear fangs are enormous, and, in one case,

Tomodon, doubly grooved.

Deviation of head scutes from the usual colubrid

pattern shows two general trends in the Philodryini

(Table 36). In twelve genera the nasal is single or

semidivided. In four genera the loreal is modified:

being large, variable, or absent. Nothopsis is unusual

in that the normal colubrid complement of head shields

is broken up and invaded by many small scales (Dunn and

Dowling, 1957).

c . Geography

The Philodryini range from a distributional center

in southern South America including Paraguay and south­

eastern Bolivia, throughout South America east of the

Andes to Venezuela and Colombia (Figure 208). Some range

southward from Peru to Argentina. From its southern base

the range of the Philodryini extends northward along both

coasts of Central America to the Isthmus of Tehuantepec.

The philodryines avoid the mountains of Central America

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TABLE 35: TRIBE PHILODRYINI - MAXILLARY DENTITION

Genus Maxillary Dentition

Amastridium 11-17+11; prediastemal teeth subequal­ sized; rear teeth grooved or not. Apostolepis 4-5+II; maxillary very short. Calamodontophis 17+11; prediastemal teeth unusually long and grooved on outer face, more strongly so posteriorly. Carphophis 8-12; maxillary teeth very small, subequal­ sized. Contia 11; maxillary teeth subequal-sized Diadophis 9-21; anterior teeth a little smaller than posterior teeth, except for last two which may be enlarged and separated. Hydrops 12-15; increase in length posteriorly. Manolepis 15+11; anterior prediastemal teeth are longest. Nothopsis 17-21+2; anterior maxillary teeth are long­ est . Philodryas 12-15+11; prediastemal teeth are subequal­ sized; fangs are large. Pseudablabes 14+11; prediastemal teeth small, subequal­ sized, fangs are enlarged. Synophis 21-27; last three teeth are enlarged. Tachymenis 5-16+II; fangs large; prediastemal teeth subequal-sized. Thamnodynastes 13-18+11; prediastemal teeth subequal­ sized, fangs are enlarged Tomodon 5-8+II; maxillary is short, fangs are enor­ mous and doubly grooved. Xenopholis 14+11; fangs are moderately enlarged.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 278

TABLE 36: TRIBE PHILODRYINI - HEAD SCUTES

Genus Deviation From Normal Colubrid Pattern

Amastridium loreal is variable: present or not.

Apostolepis 0 loreal; internasals fused with pre- frontals; nasal single; no anterior temporal; postoculars 2 or 1.

Calamodontophis head scutes normal.

Carphophis loreal large; 0 pre-, 1 postocular; small supraocular; 1 nasal; 5 supra-, 6(5) in­ fralabials .

Contia 7(6) supralabials; 7 infralabials,

Diadophis temporals 1+1.

Hydrops nostril directed upward; fused inter­ nasals .

Manolepis head scutes normal.

Nothopsis most of susal head scutes broken up.

Philodryas loreal may be absent; 4 internasals in one species.

Pseudablabes head scutes normal.

Synophis loreal may be missing; 1 prefrontal.

Tachymenis head scutes normal.

Thamnodynastes head scutes normal.

Tomodon head scutes normal.

Xenopholis single prefrontal.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. FIGURE 208: Geographic Range of Tribe Philodryini

0 = 1 genus = 2 genera

Hr = 3,4,5 genera m = 6-7 genera

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure 208.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 280

and the Yucatan peninsula. The tribe extends north

along both Mexican coasts, although the major portion of the

Mexican plateau is excluded from the range of Tribe Phil­

odryini in North America. Three genera range from Wash­

ington south through the Baja Peninsula, and through the

central and southern United States north to Nova Scotia.

Tribe Philodryini appears to be a group of snakes

which originated, perhaps from lycodontine-like ancestors,

in pre-Pliocene South America. That Tribe Philodryini

is a predominantly South American group is indicated by

its latitudinal distribution (Table 37). The majority

of species are found between 0° and 20° South Latitude.

The philodryines, therefore, are grouped with the other

southern xenodontine tribes, the Diaphorolepini, Pseudo-

boini, and Xenodontini.

d . Summary

The Tribe Philodryini as here recognized is a tribe

of xenodontine genera with noncapitate, spinose and caly-

culate hemipenes. The genera included in the present

grouping include Amastridium, Apostolepis, Calamodontophis,

Carphophis, Contia, Diadophis, Hydrops, Manolepis, Nothop­

sis , Philodryas, Pseudablabes, Synophis, Tachymenis, Tham-

nodynastes, Tomodon, and Xenopholis.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. without prohibited reproduction Further owner. copyright the of permission with Reproduced

TABLE 37: TRIBE PHILODRYINI - LATITUDINAL DISTRIBUTION STqdoquopouiBqBO s 3 q s saqBxqepnasa tnrvip-tjqsBUiv s-tdaqo^sodv b fo o ax dou sf[oq STuauiXqoBj, SBXjpoqTqa sxqdoqdaBO u£p ouureq j, STsdoqqoflj s-tqdopBfa STdaqouBw sxqdouXs uopomoj, sdoap^H S-[B^OX B-tquoo •H 4J ■U P < nl d O IrHI VO rHrH rH IrH O O I I I O r r II I I I I rH rH I—I O I O I rH O II I I I I I O rH rH O O I I I I I I 0 I O N O 00 I I I m rH rH rH O I 0 O 0 O I I I I I I I I I I I I I I I H I I I I I I I rH O I—I CM OO rH m M CM CM M M O CM o o CM rH H I rH O 1 —I 281 282

6. Tribe Pseudoboini

Tribe Pseudoboini is composed of ten genera with 41

species of xenodontine snakes which have a distributional

center in South America.

DEFINITION: Tribe Pseudoboini was recognized informally

by Bailey (1967) as a natural group of South American

snakes. Analysis of the hemipenes within this group shows

that they share a distinctive hemipenis in which the lobes

of a bilobed hemipenis are capitate. This condition,

termed bicapitate, is known in no other group, and defines

the tribe (Table 38).

a. Ecology

The Pseudoboini may be either terrestrial or arboreal,

nocturnal or diurnal; they feed on a wide variety of verte­

brates (Table 39). All are oviparous. Tropidodryas and

Phimophis are both diurnal, arboreal snakes. The former

is omnicarnivorous and the latter feeds on frogs, lizards,

and birds. The other arboreal pseudoboines, Tripanurgos

and Siphlophis, are nocturnal. Tripanurgos feeds on frogs

and lizards, while the diet of Siphlophis is unknown. Rha-

chidelus is a diurnal, terrestrial snake known to be omni­

carnivorous and to include birds in its diet. The remain­

ing three genera for which there is ecological information:

Clelia, Oxyrhopus, and Pseudoboa; are nocturnal, terrestrial

snakes. As juveniles, Oxyrhopus and Pseudoboa feed on liz-

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 283 awns awns awns awns calyces calyces awns calyces calyces awns calyces awns spines calyces spines calyces spines calyces forked spines forked spines calyces forked forked forkedforked spines spines calyces forkedforked spines forked spines forked spines Capitation Sulcus Ornamentation bicapitate bicapitate bicapitate bicapitate bicapitate bicapitate bicapitate bicapitate bicapitate bicapitate Shape bilobed bilobed bilobed bilobed bilobed bilobed bilobed bilobed bilobed bilobed Siphlophis Saphenophis Genus Clelia Drepanoides Tropidodryas Oxyrhopus Tripanurgos Pseudoboa Rhachidelus Phimophis TABLE 38: TRIBE PSEUDOBOINI - HEMIPENES

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TABLE 39 : TRIBE PSEUDOBOINI - ECOLOGY

Genus Information

Clelia terrestrial; nocturnal; feeds on snakes and other reptiles; oviparous Drepanoides feeds on lizards and snake eggs; oviparous

Oxyrhopus terrestrial; nocturnal; feeds on lizards as juveniles , adults feed on mammals

Phimophis arboreal; diurnal; feeds omnicarnivorously, but especially feeds on lizards; oviparous

Pseudoboa terrestrial; nocturnal; juveniles feed on lizards, adults feed on mammals, oviparous

Rhachidelus terrestrial; diurnal; feeds omnicarni­ vorously, includes birds in diet; oviparous

Saphenophis none

Siphlophis arboreal; nocturnal; oviparous

Tripanurgos arboreal; nocturnal; feeds on frogs and lizards; oviparous

Tropidodryas arboreal; diurnal; feeds on frogs, lizards, and birds; oviparous

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TABLE AO.: TRIBE PSEUDOBOINI - MAXILLARY DENTITION

Genus Maxillary Dentition

Clelia 10-15+11; prediastemal teeth subequal­

sized, fangs modestly enlarged.

Drepanoides 7-10+11; prediastemal teeth increase in

size posteriorly.

Oxyrhopus 10-15+11; prediastemal teeth subequal­

sized; fangs modestly enlarged.

Phimophis 11+11; prediastemal teeth subequal-sized.

Pseudoboa 10-15+11

Rhachidelus 15+11; prediastemal teeth increase slightly

in size; fangs 1 3/A size of prediastemal

teeth, last fang is offset.

Saphenophis 19-22+2; prediastemal teeth subequal-sized;

postdiastemal teeth twice as long as pre­

diastemal teeth.

Siphlophis 13-19+2; third to sixth maxillary teeth

greatly enlarged, followed by a diastema

and smaller postdiastemal teeth

Tripanurgos 13-15+11; anterior prediastemal teeth lar­

ger than postdiastemal teeth.

Tropidodryas 13-17+11; prediastemal teeth subequal­

sized; fangs weakly grooved

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 286

ards, while as adults both genera feed on mammals. Clelia

is a widely known ophiophagous snake which also includes

lizards in its diet.

The enlarged rear teeth of the Pseudoboini reflect

their specializations for feeding on relatively large­

sized vertebrates (Table 40). in only two genera the post­

diastemal teeth are enlarged, but ungrooved. Siphlophis

is unusual amongst all xenodontines in that three to five

or six of its maxillary teeth are greatly enlarged and

followed by a diastema and smaller postdiastemal teeth.

Bailey (1967) hypothesized that the Pseudoboini are evolv­

ing towards loss of prediastemal maxillary teeth, and ret­

ention as well as enlargement of the rear fangs. He bol­

stered his argument by citing the moderate to low numbers

of maxillary teeth which are characteristic of this group.

In Saphenophis the postdiastemal teeth are two times as

long as the prediastemal teeth. In Drepanoides the post­

erior teeth are flattened like sabres, a modification for

feeding on snake eggs. In Clelia, Oxyrhopus, Phimophis,

Pseudoboa, and Tropidodryas the maxillary teeth are subequal

in size and the fangs are moderately enlarged,

b. Morphology

Morphological characteristics of the Pseudoboini ref­

lect similarities within the tribe (Table 41). Body shape

is either cylindrical or feebly compressed. Total length

ranges from 540 to 2100 mm. Tail length ranges from 115-

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 287 k 4R VRE 1-4R VRE M v 15(17) s 0-2 150-177 r s 67-84 d (mm) -- comp a comp a comp comp a comp NOTE: See Table 9 for abbreviations Genus Body Body/Tail Eye D AP V A (3 TABLE 41: TRIBE PSEUDOBOINI - MORPHOLOGICAL CHARACTERISTICS Drepanoides cyl Clelia cyl, 2100/340 M,S 17-19 v s 2 197-237 s,d r, 42-93 d s, Oxyrhopus cyl 980/190 S-M 17 v s 0-2 172-236Saphenophis s,d r, 47-126 -- Siphlophis d, s 540/115 comp M 930/23015-19 r L s 0 17-21 v s 146-174 2 d 205-255 a s 51-87 98-118 d d Phimophis Pseudoboa cyl 1120/250 cyl S 1180/24017-19 v T-S s 17-19 v 2 s 2 185-211 171-208 s r, s 64-97 70-99 s d, s Rhachidelus -- 1320/310 M-L 25-29 v s 2 184 - s 88 d s, Tripanurgos comp 1080/250 L 17 v s 2 228-258 a s 80-125 d Tropidodryas cyl 1236/219 M-L 21 r s 2 179-224 r s,d 88-106

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 288

340 mm. Clelia is the largest member and Saphenophis is

the smallest. The eye is small to large. Saphenophis

and Tropidodryas have round pupils, while the other eight

genera have vertical pupils. The number of dorsal scale

rows is relatively consistent within the tribe, ranging

from 15 to 21 in most cases, although Rhachidelus has 25-

29 dorsal scale rows. Dorsal scales are smooth with the

exception of one species of Tropidodryas which has keeled

scales. The vertebral scale row is somewhat enlarged in

Rhachidelus and strongly enlarged in Tripanurgos. The for­

mer, although it is a terrestrial snake also eats birds,

while the latter is an arboreal snake. In Saphenophis

the number of dorsal scale rows is reduced through the

loss of the fourth row.

Most Pseudoboini have two or no apical pits, although

in species of Drepanoides and Oxyrhopus the number of apical

pits varies from 0-2. The number of ventral scutes ranges

from a minimum of 146-174 to a maximum of 228-258. Ventral

scutes are rounded or angulate in three genera, rounded

in two genera, and angulate in two. Anal plates are single

in six genera, single or divided in three genera, and div­

ided in one genus. The number of caudal scutes ranges

from a minimum of 42-93 to a maximum of 80-125. Caudal

scutes are divided in four genera, both single and divided

in four genera, and single in one genus.

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Members of the Pseudoboini also exhibit similar vari­

ations of head scutes from the normal colubrid plan (Table

42). The loreal is single, very small, absent, or fused

to adjoining scales in Clelia, Drepanoides, Phimophis,

Rhachidelus, and Saphenophis. The usual pseudoboine pre-

and postocular scale pattern is 1 pre- and 2 postoculars,

although Siphlophis has 4 postoculars. Temporal scales

range from 1+1, 1+2, 2+2, 2+3 to 3+4 in pseudoboine genera.

Five genera have variations in the normal number of sup-

ralabial scales.

The hemipenes of the Pseudoboini also show a character­

istic pattern in which a capitation of calyces is confined

to each lobe of a bilobed hemipenis (Table 38). This pse­

udoboine kind of hemipenis, termed bicapitate, is distin­

guished from a capitate condition in which the capitulum

is confined to a single, sometimes slightly bilobate apex,

or semicapitate in which there is no distinct demarcation

of the capitulum. Pseudoboine hemipenes have forked sulci

and proximal spines. Six of the ten pseudoboine genera

also have medial awns ornamenting the calyculate apices of

their bicapitate hemipenes.

c . Geography

Confined to the neotropics, the pseudoboines appear

to have their distributional center in Matto Grosso, Bra­

sil and adjacent Bolivia (Figure 209 ). From this center

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TABLE 42: TRIBE PSEUDOBOINI - HEAD SCUTES

Genus Variation From Normal Colubrid Plan

Clelia preocular just reaching upper surface of head or not; 1 or 0 loreal.

Drepanoides 0 loreal or loreal very small; temporal 1+1 or 2+1; 6 supralabials.

Oxyrhopus head scutes normal.

Phimophis rostral sharply pointed and curved back; 0 loreal (1 species).

Pseudoboa head scutes normal.

Rhachidelus loreal fused to posterior nasal; temporals 3+4.

Saphenophis 1 nasal; loreal fused with preocular; pre­ ocular large and single; 2 postoculars; fusion of ocular loreal region not unusual.

Siphlophis head scutes normal.

Tripanurgos head scutes normal.

Tropidodryas temporals small, scale-like, 2, 2+3, or 3 temporals; infralabials 5.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 291

FIGURE 209: Geographic Range of Tribe Pseudoboini

0 = 1 genus

::: = 2 genera

:EE = 3-5 genera

• = 6-7 genera

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure 209. 292

they are found as far south as 40° South Latitude in Arg­

entina. There is a subsidiary center of concentration in

the Guianas and eastern Venezuela. The tribe crosses the

Andes in Colombia and is found in coastal Colombia, Ecua­

dor, and to 15° South Latitude in coastal Peru. Two gen­

era range northward into Central America, and two genera

include southern Mexico in their ranges.

The latitudinal distribution of Tribe Pseudoboini

shows a preponderance of species distributed south of the

equator. Most species are found between 11° to 30° South

Latitude. Tribe Pseudoboini, along with Tribes Diaphoro-

lepini, Philodryini, and Xenodontini, is a southern xeno-

dontine tribe (Table 43).

d. Discussion and Relationships

Bailey (1967) suggested that the pseudoboine genera

had morphological similarities and informally proposed the

tribal appellation Pseudoboini. Members of the Pseudo­

boini were previously grouped into the Dipsadini (Dowling

and Duellman, 1978). Because of morphological similari­

ties, and the distinctive bicapitate hemipenis, the Tribe

Pseudoboini appears to be a natural assemblage of South

American xenodontine snakes. The Pseudoboini occupy a

position intermediate between tribes Philodryini and

Xenodontini.

As here recognized, Tribe Pseudoboini consists of

ten xenodontine genera characterized by possession of bi-

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE A3: TRIBE PSEUDOBOINI - LATITUDINAL DISTRIBUTION

Siphlophis Saphenophl^, tr* rt H* r t C CL fl> Tripanurgos Pseudoboa Rhachidelus Drepanoides Oxyrhopus Phimophis o 1 1 Clelia + h-i 53 Ul » h- SI Ln o o 1 1 4> OO SI to i—* o CO O O I 0 o o o h-i h-» to S! SI o O I I (-‘I-* o o o (-‘I-* Total i i i i i Tropidodryas H* SI O t—1 ro o i — 1 o o »-* o h-» tO CO CO i—‘ i o o 0 o o o to o o 1 o h- ■P- u> o CO O O I—1 O'* 00 hO 00 O O'* O I—1 o o o o o o o 1 1 1 1 1 1 1 1 i i o r—1 oI i I i I i O i h o -O i N 3 O I i o r o I o lot'orooi i—* CO CO CO 4> U i o ONJ>\00'0'f-0 I O Ni CO NJ (—* I—1 O I I O N3 OO (jO N3 I—‘ I—1 O O (jO N3 N3 OO I—‘ I—1 I » o I I I o i i + 1— co Ui O CO I—1 ho N3 t—'I—1 N3 ho O I—1 CO

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 294

capitate, bilobed hemipenes with forked sulci, proximal

spines, and often, medial apical awns. The tribe includes

Clelia, Drepanoides, Oxyrhopus, Phimophis, Pseudoboa,

Rhachidelus, Saphenophis, Siphlophis, Tripanurgos, and

Tropidodryas.

7. Tribe Xenodontini

Tribe Xenodontini includes nine genera with 69 species

of xenodontine snakes which have central South America

as a center of distribution.

DEFINITION: Tribe Xenodontini is defined by possession of

a bilobed hemipenis which has apical disks,

a. Ecology

Members of Tribe Xenodontini display wide variations

in diet and habitat, although all are diurnal and ovipar­

ous. These snakes feed on fishes, lizards, reptile eggs,

birds, and rodents (Table 44). Insects are also recorded

as an item of diet, but this finding is questionable. It

is more likely that the arthropods were originally consum­

ed by another prey item ( a frog for example ) and were

subsequently retained within the snake's stomach, unaff­

ected by its digestive processes.

The available information on habitat preference sim­

ilarly reflects the diversity of this tribe (Data section).

Erythrolamprus, for example, is found in rainforests as

well as in xeric areas, while Umbrivaga, on the other

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TABLE 44: TRIBE XENODONTINI - ECOLOGICAL INFORMATION

Genus Ecological Information

Dromicus terrestrial, semiaquatic; diurnal, feeds on

frogs.

Erythrolamprus terrestrial; diurnal, feeds on frogs, liz­

ards, amphibians, eels, small rodents;ovi­

parous .

Leimadophis arboreal; feeds on frogs, lizards, birds,

rodents, oviparous.

Liophis terrestrial, aquatic; feeds in insects,

fishes, frogs, toads, lizards, birds.mam­

mals; oviparous.

Lygophis arboreal; feeds on lizards, birds, rodents,

Lystrophis feeds on insects, frogs, lizards; ovipar­

ous .

Umbrivaga feeds on reptile eggs

Waglerophis terrestrial; feeds on toads; oviparous,

Xenodon terrestrial, riparian; diurnal; feeds on

frogs, toads, tadpoles, birds, rodents;

oviparous.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 296

hand, is an inhabitant of shadowy cloud forests,

b . Morphology

The diversity of members of Tribe Xenodontini is

further reflected in their external morphology, set forth

in Table 45. Body shape ranges from depressed to cylind­

rical to compressed. Total length ranges from 392 to 1040

mm. Tail length ranges from 80 to 200 mm. Eyes vary from

small to large. All Xenodontini have a round pupil, which

indicates diurnal activity.

Number of dorsal scale rows varies from 15 to 25.

Dorsal scales are usually smooth with 1 apical pit. Two

genera are recorded as having "apical pits", with no in­

dication given as to explicit number. Ventral scutes

are angulate or rounded. Number of ventral scutes ranges

from 122 to 254. The anal plate is usually divided. The

number of caudal scutes varies from a minimum of 25-49 to

a maximum of 79-94. Caudal scutes are usually divided,

although they may be single.

Head scutes follow the normal colubrid pattern, with

few variations (Table 46). Maxillary dentition of the

Xenodontini reflects the divergence of these snakes from

the hypothesized ancestral form, which presumably had many,

subequally sized teeth on a normal sized maxillary.(Table 47).

Liophis, with no diastema and many maxillary teeth reflects

this presumed basic plan. Some members of Tribe

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 297 d d d s - 72-94 d 51-100+ 38-6145-75 d 45-80 C 25-49 29-60 O d d d d A d 38-48 d 35-42 d - - r d r d - a d - a a s 137-200 a 172-204 V 133-173 122-154 132-157 0-1 CHARACTERISTICS 0 0 143-170 AP + + s s s 1 132-182 - s 0 s s 1 126-168 r 15-19 15-25 15-19 17,19 17-19 s 0 137-178 D 15-17 17-21 19 r r S-L Eye M-L r M r L r M r 19-21 s L r - - MORPHOLOGICAL (mm) 1000/200 730/125 Body/Tail 650/190 392/102 r 660/80 1040/130 L 1 cyl comp 780/105 Body cyl si dep TRIBE XENODONTINI TABLE 45: Genus Drotnicus Erythrolamprus Leimadophis cyl Liophis Lygophis cyl Umbrivaga Lystrophis scyl Waglerophis Xenodon cyl 548/90 NOTE: See Table 9 for abbreviations.

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TABLE 46: TRIBE XENODONTINI - HEAD SCUTES

Genus Variation From Normal Colubrid Plan

Dromicus temporals 1+1; 8 or 9 supralabials.

Erythrolamprus 1 pre-, and 2 postoculars; temporals 1+2 (1+1); 7 supralabials.

Leimadophis head scutes notrmal.

Liophis 6-8 supralabials.

Lygophis head scutes normal.

Lystrof his anchor-shaped rostral; 0-2 suboculars.

Umbrivaga head scutes normal.

Waglerophis 1-3 postoculars; 1-2 suboculars.

Xenodon 0 suboculars; 2 postoculars; 7 supra-, 9 infralabials.

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TABLE 47: TRIBE XENODONTINI - MAXILLARY DENTITION

Genus Maxillary Dentition

Dromicus 15+2; postdiastemal teeth strongly enlarged

Erythrolamprus 10-15+11; fangs feebly enlarged

Leimadophis 18-23+2; postdiastemal teeth twice the size

of prediastemal teeth.

Liophis 20-24; posterior teeth slightly enlarged.

Lygophis 18-22+11.

Lystrophis 4-5+2; maxilla is short, postdiastemal

teeth are large: 3 times the size of the

prediastemal teeth.

Umbrivaga 6-12+2; posterior maxillary teeth are enl­

arged, lancet-shaped, and almost horizontal.

Waglerophis 6-7+2.

Xenodon 6-15+II; prediastemal teeth increase post­

eriorly; fangs strongly enlarged.

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Xenodontini have a diastema as well as enlargement of the

pair of teeth posterior to it. Droinicus has strongly enl­

arged postdiastemal teeth. In Leimadophis the rear teeth

are twice as large as the prediastemal teeth, while in

Lystrophis the rear teeth are three times the size of the

prediastemal teeth. Those xenodontini with rear fangs

show variations of a trend toward enlargement of these

fangs. In Erythrolamprus the fangs are only feebly en­

larged, while in Xenodon on the other hand, the fangs are

strongly enlarged.

Another trend in the Xenodontini is toward loss of

prediastemal teeth and shortening of the maxillary bone.

Waglerophis. with no rear fangs, has relatively few max­

illary teeth on a normal-sized maxilla; while Lystrophis

has a short maxilla, very few (4-5) maxillary teeth, and

thrice-enlarged, but ungrooved, rear teeth. Umbrivaga has

distinctive posterior maxillary teeth which are enlarged,

lancet-shaped, and almost horizontal. It is hypothesized

that these unusual posterior maxillary teeth are speciali­

zations for egg eating.

Although the Xenodontini are morphologically and ecol­

ogically diverse, their hemipenes reveal a basic similarity:

all are bilobed with a forked sulcus spermaticus, and

spinose with distinctive apical disks (Table 48). The

apical disks are found in no other Western Hemisphere

snakes.

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TABLE 48: TRIBE XENODONTINI - HEMIPENES

Genus Shape Capitation Sulcus Ornamentation

Dromicus weakly none forked spines discs or not bilobed

Erythrolamprus bilobed none forked spines discs

Leimadophis bilobed none forked spines discs

Liophis bilobed none forked spines discs

Lygophis bilobed none forked spines discs

Lystrophis bilobed none forked spines discs

Umbrivaga bilobed none forked spines discs

Waglerophis bilobed none forked spines discs

Xenodon bilobed none forked spines discs

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c. Geography and Discussion

The range of Tribe Xenodontini is centered in central

and Amazonian Brazil (Figure 210). The tribe radiates in

all directions from this center, but crosses the Andes

only in Colombia and Ecuador, presumably via Venezuela.

Single genera have dispersed from Venezuela to the Lesser

Antilles as far north as Guadeloupe, and through Central

America as far north as southern Mexico. Other genera

have dispersed southward to central Argentina.

The latitudinal distribution of Tribe Xenodontini

(Table 49) indicates that most genera are found south

of the equator, and that Tribe Xenodontini is one of

four southern tribes of the subfamily.

Thus, the Xenodontini as here recognized is a tribe

that originated in central South America and subsequently

radiated to the Lesser Antilles, Central America, and

Mexico in post-Pliocene times. No revision has been

made of Dowling and Duellman's (1978) grouping which assigns

9 genera with 69 species to this tribe. The members of

Tribe Xenodontini include Dromicus, Erythrolamprus,

Leimadophis, Liophis, Lygophis, Lystrophis, Umbrivaga,

Waglerophis, and Xenodon.

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FIGURE 210: Geographic Range of Tribe Xenodontini

= 1 genus

= 2 genera

~ = 3-4 genera

S =5-7 genera

V

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure 210.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE 49: TRIBE XENODONTINI-LATITUDINAL DISTRIBUTION

Erythrolamprus Umbrivaga Total Liophis Lygophis Lystrophis Waglerophis Leimadophis Xenodon to rt rt C Cu (0 0 • • Dromicus + H* I—* Z ■fc- Cn (-» Z o Cn CO o to l-» t-* z z CO 1 0 o o 0 1 1 1 1 (—* to a o I I o o 0 o 0 1 z o o o o 1—< o o 0 0 o o r-*to 1— to o o o o o CO 4>o CO -P- Cn oo vo o --J o vo oo Cn -P- o 0 o o 1 1 i i 1 (-* h-» t—* CO CO CO CO CO o Cn OCOO-C-VOvOI-JOl OHNNWWUHO o i i o (—1 i—1 co cn -t> o i o -t> cn co i—1 I I (—1 Oo i I—1 i I—1 t o O'! Cn O I I O Ul Ul 4> 00 -C- CO O I I O H-* to CO I—* I—1 O I I I I—1 I—* CO to I O H-* I O CO CO to i O o I I I I i i i i o to i—1 i—* o i I I + 1—* CO Cn o o h j torotocoi-*i-»©oo

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8. Northern and Southern Xenodontine Tribes

Examination of the ranges of the seven xenodontine

tribes reveals two general distributional patterns. Tri­

bes Alsophiini, Dipsadini, and Leptodeirini are centered

in Hispaniola, central-southern Mexico to northern Costa

Rica on the Caribbean versant, and northern Pacific coa­

stal Mexico, respectively (see Figures 204, 206, and 207).

Their latitudinal distributions reflect a northern affin­

ity (Figure 211), with most species distributed between

11° and 20° North Latitude. Tribes Diaphorolepini, Philo­

dryini, Pseudoboini, and Xenodontini, in contrast, are

centered in southern and central South America (see Fig­

ures 205, 208, 209, and 210). The latitudinal distribu­

tions of these tribes show a southern affinity (Figure

211), with most species distributed between 10° North and

30° South Latitude. Thus, Subfamily Xenodontinae has

northern and southern tribes.

The differences between the northern and southern

tribes are reflected in the type of maxillary dentition,

as summarized in Table 50 and detailed in Tables .51-53.

Of 27 northern genera (the edentate anterior maxillary of

Sibynomorphus prevents its inclusion in these data),

7 percent possess rear fangs, while 93 percent have no

fangs (Table 51). Of the 45 southern genera, 60 percent

possess rear fangs, while 40 percent have no fangs (Table

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FIGURE 211: Latitudinal Distribution of Subfamily

Xenodontinae

— number of species in South America

IIIIH = number of species in Central Amer­

ica, Mexico, North America.

Key to Features of Hemipenis Diagrams

= bilobed

‘t? = single

Y = forked sulcus

) = single sulcus

*2°° = calyces

X ,'*» = spines

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sr+ v V • - w n** * in iw w • • : « i < ^ c c < •:< c c •: t «i ^ < ft i u NiHiaon iiH N tu fia m ^ m « n « n i m | i » 5 & a» 0

fL O rt. o - o ai NaiNinoa i ia ia s n*f in H o CO •-j 0 0 0 0 ____ 0 0 i m 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 2 Q 2 P i 1 0 0 0 2 Q tn 1 0 1 1 0 0 2 0 m i P Q 0 0 0 2 0 0 0 0 0 i m P 2 Q 2 Short Maxilla i m 1 0 0 0 0 2 Q P 0 0 0 0 0 _____ 1 1 0 1 1 1 0 0 0 i Q 2 2 m i P 2 Q 2 0 3 1 2 0 0 i 3 0 6 3 1 tn Q 2 0 2 8 0 6 i O 2 f i - i 2 i pM 2 Q 0 0 0 3 0 Normal-Length Maxilla i m 1 1 0 0 0 1 0 0 0 0 5 2 2 0 P Q m i 0 0 1 0 2 0 0 P 2 Q S3 Few Teeth Mod. Teeth Many Teeth Few Tee~tK Mod. Teeth _____

j 1 rt cu co rt B 0 co 00 O s + Q 2 •H 2 3 1 5 2 0 cu rt B CO rt co 00 G rt o •u 3 1 3 •H Q 8 3 3 2 0 pM , 1 1 3 9 4 5 co 00 S cc) co % rt +J Pn Pn •H O 10 4 CO u CD

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TABLE 51: NORTHERN AND SOUTHERN TRIBES: Fangs vs No Fangs

No. of Genera Fangs No Fangs

NORTHERN TRIBES Alsophiini 11 0 11 Dipsadini 13 1 12 Leptodeirini _4 _1 _3

28 2 26

SOUTHERN TRIBES Diaphorolepini 10 4 6 Philodryini 16 10 6 Pseudoboini 10 8 2 Xenodontini _9 _5 _4

45 27 18

TABLE 52: NORTHERN AND SOUTHERN TRIBES: No. of Teeth

No. of No. of Maxillary Teeth Genera Few Moderate Many NORTHERN TRIBES Alsophiini 11 1 8 2 Dipsadini 12* 1 10 1 Leptodeirini 4 _1 _3 _0 27 3 21 3

SOUTHERN TRIBES Diaphorolepini 10 6 3 1 Philodryini 16 4 11 1 Pseudoboini 10 2 8 0 Xenodontini 9 _3 _5 _1 45 15 27 3 *Sibynomorphus not included

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51).

Differences between the northern and southern tribes are

also seen in the number of maxillary teeth (Table 52).

In the northern tribes 11 percent of the genera have few

teeth, 74 percent have a moderate number of teeth, and 15

percent have many teeth. In the southern tribes, in con­

trast, 33 percent have few teeth, 60 percent have a mod­

erate number of teeth, and 6 percent have many teeth.

Length of the maxilla provides another difference

between northern and southern groups (Table 53). Of 28

northern genera, 7 percent have a short maxilla, and 93

percent have a normal-length maxilla. In the southern

tribes, in contrast, 15 percent have a short maxilla and

85 percent have a normal-length maxilla. These distinctions

in maxillary dentition and length of maxilla reinforce the

differences observed in the geographic affinities of the

northern and southern tribes.

A final difference between the northern and southern

tribes is observed in the mode of scale row reduction.

Although modes of scale row reduction are only irregularly

reported, a literature survey reveals that only the north­

ern tribes Alsophiini, Dipsadini, and Leptodeirini reduce

the number of posterior scale rows through the loss of

the paravertebral rows. The southern tribes, in contrast,

reduce the number of posterior scale rows through the loss

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TABLE 53: NORTHERN AND SOUTHERN TRIBES: Length of Maxilla

No. of Genera Short Maxilla Normal Maxilla NORTHERN TRIBES Alsophiini 11 1 10 Dipsadini 13 1 12 Leptodeirini _4 _0 _4 28 2 26

SOUTHERN TRIBES Diaphorolepini 10 4 6 Philodryini 16 2 14 Pseudoboini 10 0 10 Xenodontini _9 __1 _8

45 7 38

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of the third, fourth, or seventh rows. The paravertebral

rows are never reported as lost in the southern tribes.

A complete survey of the mode of scale row reduction

amongst all xenodontine genera must be made before this

final distinction between the northern and southern tribes

can be considered more than tentative. Such a survey is

beyond the scope of the present work.

9. History of the Southern and Northern Tribes.

Present evidence suggests that the southern and north­

ern tribes share a common ancestor, but have separate his­

tories . The Diaphorolepini, Philodryini, Pseudoboini,

and Xenodontini form a cohesive southern unit. The ext­

ensions of these tribes into Mexico and North America

(Figures 205, 208, 209, and 210) involve few genera and

few species and are best described as tentative northern

forays. It is likely that these four tribes originated

from a common Gondwanaland ancestor, similar to the Eocene

African colubrid, Nigerophis. This ancestor was isolated

in South America when Gondwanaland was separated into

Africa and South America. The southern tribes evolved

and differentiated in the 50 million years before South

and Middle America joined in the late Pliocene. Corrobora­

tion for a Gondwanaland ancestry for the southern tribes,

and thus for all xenodontines, is found in the recent dis­

covery of a disked hemipenis in Madagascarophis, an unusual

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rear-fanged snake from Madagascar (Dowling, pers. comm.).

An alternate hypothesis would evolve the xenodontines

from a lycodontine ancestor. The hemipenes of the four

southern tribes: entirely spinose; noncapitate with

spines and calyces; bicapitate; and disked; also seem to

be a natural series. The entirely spinose hemipenis of

the Diaphorolepini points to a lycodontine ancestor.

The distribution of the Alsophiini (Figure 204) may

give a clue to the manner in which the northern tribes

differentiated from the southern tribes. The ancestors

of the northern tribes may have been South American xeno­

dontines with a noncapitate hemipenis with a forked sulcus

(such as is now seen in Tribe Philodryini), which dispersed

from the South American mainland via the Lesser Antilles.

These evolved into Alsophiini with semicapitate hemipenes.

Subsequent island-hopping allowed the Alsophiini to reach

the Greater Antilles, the Middle American mainland, and

the North American mainland. Those reaching the Middle

American mainland developed a capitate hemipenis and be­

came what are presently recognized as the Dipsadini. Dip-

sadines isolated on the southern Pacific coast of Mexico

and on the Baja Peninsula lost one fork of the sulcus and

became the leptodeirines. The hemipenes of the three

northern tribes form a natural series: semicapitate with

forked sulcus; capitate with forked sulcus; and capitate

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with simple sulcus. The Leptodeirini and Dipsadini reent­

ered South America in post-Pliocene times.

10. Revised Taxonomy of Subfamily Xenodontinae

Immunological and electrophoretic studies now under­

way at the University of Maryland may give information as

to the degree of relatedness of the northern and southern

groups of xenodontines, and will either confirm or falsify

the foregoing hypothesis as to the history of Subfamily

Xenodontinae. Until this information is available, Tribes

Alsophiini, Dipsadini, and Leptodeirini are placed into

Section I of Subfamily Xenodontinae in recognition of their

common northern distributions, lack of fear fangs, high

percentage of a moderate number of teeth, normal-length

maxilla, and paravertebral mode of scale row reduction.

Tribes Diaphorolepini, Philodryini, Pseudoboini, and Xeno-

dontini are placed in Section II of Subfamily Xenodontinae

in recognition of their southern distributions, possession

of rear fangs, high percentage of members with few or

moderate numbers of teeth, higher percentage of members

with a shortened maxilla, and having scale row reductions

which do not involve the paravertebral rows. A revised

listing of the tribal allocations of Subfamily Xenodontinae

is set forth in Table 53.

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TABLE 54: SUBFAMILY XENODONTINAE - REVISED TAXONOMY

Section I: Northern Tribes -Tribe Alsophiini: Hemipenis semicapitate* Alsophis, Antillophis, Darlingtonia, Farancia, Helicops, Heterodon, Hydrodynastes , Hypsr’.rhynchus, Uromacer, Uromacerina, Arrhyton. -Tribe Dipsadini: Hemipenis capitate. Adelphicos, Coniophanes, Cryophis, Dipsas, Geophis, Ninia, Pliocercus, Rhadinaea, Sibon, Sibynomorphus, Tretanorhinus, Trimetopon, Tropidodipsas. -Tribe Leptodeirini: Hemipenis capitate, simple sulcus. Eridiphas, Hypsiglena, Imantodes, Leptodeira.

Section II: Southern Tribes -Tribe Diaphorolepini: Hemipenis entirely spinose. Atractus, Chersodromus, Crisantophis, Diaphorolepis, Elapomorphus, Enulius, Gomesophis, Pseudotomodont Ptychophis, Sordellina. -Tribe Philodryini: Hemipenis noncapitate, spinose and calyculate. Amastridium, Apostolepis, Calamodontophis, Carphophis, Contia, Diadophis. Hydrops, Manolepis, Nothopsis, Phi- lodryas, Pseudablabes, Synophis, Tachymenis, Thamno- dynastes, Tomodon, Xenopholis. -Tribe Pseudoboini: Hemipenis bicapitate Clelia, Drepanoides, Oxyrhopus, Phimophis, Pseudo­ boa, Rhachidelus, Saphenophis, Siphlophis, Tripanurgos, Tropidodryas. -Tribe Xenodontini: Hemipenis disked. Dromicus, Erythrolamprus, Leimadophis, Liophis, Lygophis, Lystrophis, Umbrivaga, Waglerophis, Xenodon.

*A11 tribes except Leptodeirini have forked sulcus.

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SUMMARY

1. Scolecophis, Simophis, Tantilla, and Trimorphodon

are transferred to Subfamily Colubrinae.

2. The tribal allocations of genera with flounced

hemipenes (Conophis, Ialtris, Pseudoeryx, and some species

of Atractus and Coniophanes are deferred until the tax­

onomic significance of flounced hemipenes is ascertained.

3. Ditaxodon, Elapomo.jus. Hydromorphus, Lioheter-

ophis, Parapostolepis t Paraptychophis, Platynion, Tantal-

ophis, and Tantillita are excluded from tribal allocations

because of inadequate hemipenial descriptions.

4. Hydromorphus may have a dipsadine hemipenis, but

no description is available.

5. The 73 remaining xenodontine genera are grouped

into seven tribes based on hemipenial allocations. New

or redefined tribes are indicated by an asterisk.

a. Tribe Alsophiini is defined by possession of a

bilobed, semicapitate hemipenis with proximal spines,

distal calyces, and forked sulcus. Alsophis, Antill-

ophis, Arrhyton, Darlingtonia, Farancia, Helicops,

Heterodon, Hydrodynastes, Hypsirhynchus, Uromacer,

and Uromacerina are assigned to Tribe Alsophiini

b. Tribe Diaphorolepini* is defined by possession

of an entirely spinose, noncapitate hemipenis with a

forked sulcus. Atractus, Chersodromus, Crisantophis,

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Diaphorolepis, Elapomorphus, Enulius, Gomesophis,

Pseudotomodon, Ptychophis, and Sordellina are assigned

to Tribe Diaphorolepini. The heterogenity of hemipenes

of species within the genera Atractus and Arrhyton

suggests that they may be composite genera.

c. Tribe Dipsadini is defined by possession of a fully

capitate hemipenis with proximal spines and a forked

sulcus. Adelphicos, Coniophanes, Cryophis, Dipsas,

Geophis, Ninia, Pliocercus, Rhadinaea. Sibon, Sibyn-

omorphus, Tretanorhinus, Trimetopon, and Tropidodipsas

are allocated to Tribe Dipsadini,

d. Tribe Leptodeirini* is defined by possession of a

fully capitate, single or bilobed hemipenis with a

simple sulcus. Eridiphas, Hypsiglena, Imantodes, and

Leptodeira are allocated to Tribe Leptodeirini. If

Adelphicos proves to have a simple sulcus, it may be

allocated to this tribe.

e. Tribe Philodryini* is defined by possession of a

bilobed or single, noncapitate hemipenis with a forked

sulcus, proximal spines, and distal calyces. Amastri-

dium, Apostolepis, Calamodontophis, Carphophis, Contia,

Diadophis, Hydrops, Manolepis, Nothopsis, Philodryas ,

Pseudablabes, Synophis, Tachymenis, Thamnodynastes,

Tomodon, and Xenopholis are assigned to Tribe Philo­

dryini .

f. Tribe Pseudoboini* is defined by possession of a

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bilobed, bicapitate hemipenis with forked sulcus, prox­

imal spines, and often medial apical awns. The term

bicapitate is coined to define the condition in which

a capitulum of calyces is restricted to each apex of a

bilobed hemipenis. Clelia, Drepanoides, Oxyrhopus,

Phimophis, Pseudoboa, Rhachidelus, Saphenophis, Siph-

lophis, Tripanurgos, and Tropidodryas are allocated to

Tribe Pseudoboini.

g. Tribe Xenodontini is defined by possession of a

bilobed hemipenis which has a forked sulcus, proximal

spines, and apical disks. Dromicus, Erythrolamprus,

Leimadophis, Liophis, Lygophis, Lystrophis, Umbrivaga,

Waglerophis, and Xenodon are assigned to Tribe Xenodon­

tini.

6. Although vegetation, altitude, and climate are

important in defining the ranges of species, they are less

significant in defining the ranges of genera. The ranges

of tribes cross vegetational, altitudinal, and climatic

barriers. Each tribe has members which occupy a wide spec­

trum of ecological niches. Terrestrial, fossorial, aquatic,

semiaquatic, and arboreal as well as nocturnal, and diur­

nal forms are found in each tribe. Feeding habits within

tribes are similarly diverse. Thus, the importance of

ecology has a pattern similar to that of the significance

of vegetation, altitude, and climate. Ecology is most

significant at the specific level, often is unimportant at

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the generic level, and appears to be irrelevant at the

tribal level.

7. In contrast, the configuration of the hemipenis was

the only characteristic (morphological or ecological)

which was found to be consistent and significant at the

tribal level. Details of maxillary dentition were found

to be patterned, but not nearly as consistent as the

configuration of the hemipenis.

8. Examination of the centers of distribution of the

seven tribes revealed a division into northern and south­

ern tribes. Tribes Alsophiini, Dipsadini, and Leptodei­

rini have northern distributions, while Tribes Diaphoro­

lepini, Philodryini, Pseudoboini, and Xenodontini have

southern distributions.

9. The following differences in maxillary dentition are

observed between genera of the northern and southern

tribes:

______Percentage of Genera_____ Northern Tribes Southern Tribes

Pangs 7% 60%

No Fangs 93% 40%

Few Teeth 11% 33%

Moderate No. of Teeth 74% 60%

Many Teeth 15% 6%

Short Maxilla 7% 15%

Normal-Length Maxilla 93% 85%

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10. The northern tribes have scale row reductions

which involve the paravertebral rows. In the southern

tribes the paravertebrals are never reported as reduced.

11. It is hypothesized that the southern tribes

evolved from a Gondwanaland lycodontine ancestor. Mem­

bers of Tribe Diaphorolepini retain a lycodontine-like,

entirely spinose hemipenis, although the spines are not

arranged in chevrons as are those on lycodontine hemi­

penes. Tribe Philodryini, with calyces on a noncapitate

hemipenis, is the base group for the six other tribes.

The northern groups may have originated from a philodryine

ancestor which dispersed from the northern coast of

South America to the Lesser Antilles in pre-Pliocene times.

It subsequently developed a semicapitate hemipenis.

Island-hopping extended the distribution of the pre-als-

ophines to the Greater Antilles, as well as the Central

and North American mainlands. Alsophines reaching the

Central American mainland via the Greater Antilles dev­

eloped a fully capitate hemipenis and became dipsadines.

Dipsadines at the northwestern portion of the tribal

range lost one fork of the sulcus and became the lepto-

deirines.

In post-Pliocene times the Dipsadini and Leptodeirini

extended their ranges southward into South America,

while the southern tribes extended their ranges northward

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to colonize Central America, Mexico, and portions of

North America.

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REFERENCES

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Alvarez del Toro, M. 1960. Los reptiles de Chiapas. Tuxtla Gutierrez, Chiapas, Mexico. 204p.

Amaral, A. 1921. Ultimos trabalhos ineditos de J. Flouren- cio Gomes: "Duas novas especies de colubrideos opisthoglyphos brasilieiros (Philodryas oligo- lepis e Apostolepis longicaudata)". Annaes Paulistas de Medicina e Cirurgia. 9^(7): 1-7.

------1923. New genera and species of snakes. Proc. New Engl. Zool. Club. 8^: 85-105.

------1930. Estudos sobre ophidios Neotropicos. Mem. Inst. Butantan. 4/. 1-68.

------1930b. Estudos sobre ophidios Neotropicos. XVII. Lista remissiva dos ophidios da regiao Neo- tropica. Mem. Inst. Butantan 4_: viii +271 p.

------1930c. Contribuicao ao conhecimento dos ophidos do Brasil. IV. Lista remissiva dos ophidos do Brasil. Mem. Inst. Butantan 4_: VI + 125 p.

------1935. Contribuicao ao conhecimento dos ophidos do Brasil. VII. Novos generos e especies de Colu­ brideos opisthoglyphos. Mem. Inst. Butantan. 9: 203-204.

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Schwartz, A. and R. Thomas. 1960. Four new snakes (Tropid- ophis, Dromicus, Alsophis) from the Isla de Pinos and Cuba. Herpetologica. 16(2): 73-90.

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1971. The snake genus Amastridium in Oaxaca, Mex­ ico. Great Basin Natur. 31(4): 254-255.

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Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. BIOGRAPHICAL SKETCH -- JANANN JENNER

EDUCATION: 1962-65 West Chester State College, BS (Biology) 1973-78 New York University, MS (Biology) 1978-81 New York University, PhD Candidate (Biology)

WORK EXPERIENCE: Full Time 1960-61 G.D. Searle & Co, Skokie, 111. Lab Technician 1965-66 Bellport Sr. HS--General Science Teacher 1966-67 Cornell Medical School— Microbiology Lab Technician 1967-69 American Museum of Natural History-- Instructor, Dept, of Education 1969-75 St. David's School--Head of Science Department (N-8th Grades) 1975-76 New York University--Teaching Fellow 1976-78 New York University--Part Time Instructor 1977-81 Boyle-Midway, Cranford, N.J. --Tech­ nical Documentalist Part Time 1969-76 American Museum of Natural History, Louis Calder Saturday Workshop for Giften Children 1975 Boys' Harbor--Science Teacher TEACHING EXPERIENCE: Primary Education: St. David's School: developed and implemented science progam (Nursery through 8th grades; designed new science facility. Secondary Education: Bellport Senior High School: 9th grade General Science. Museum Education: World We Live In Program (AMNH); Used exhibits and specimens to teach NYC school children about the natural world.

Saturday Worlshop for Gifted Children: (AMNH): Developed Saturday Workshop. Designed and taught courses.

permission of the copyright owner. Further reproduction prohibited without permission. College: Teaching Fellow: Physiology, Natural History of Vertebrates, Herpetology: Reptiles, Field Studies in Zoology (Southeastern US), Field Studies in Herpetology (Hardeeville, SC). Instructor: Principles of Biology, Principles of Zoology, Field Studies in Zoology (Hardeeville, SC).

FIELD WORK:

Five seasons of volunteer work on Great Gull Island: Roseate and Common Tern Life Histories.

Operation Pond Probe: Field work in Central Park. Televised on ABC and CBS.

Machias Seal Island, Maine: Arctic Tern Band Recovery Project. Sponsored by Audubon Society of Massachusetts.

Herpetological collecting, insect collecting, ecological analysis: Southeastern US and Colima, Mexico.

PUBLICATIONS: Jenner, J. and H.G. Dowling. 1979. Principles of Zoology. HISS Publications. New York, v+165 p.

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