TIte[nuur loán (Serpentes: Colubridae) of Costa Rica: two or three species?

Jay M. Savage Dpl of Biology, University ofMiami,Box 249118, Coral Gables, R. 33124 Nonnan J. Scott, Jr. u.s. Fish and WDdlife Semce. DenverWildlife Research Center. Dpt. of Biology, Univenity oCNew Mexico, Albu· querque, New Mexico 87131.

(Received forpubtication Septernber 28, 1984)

"Abstract. /mIlntodes inont/ltw and Imllntodes cenchQQ are cunentlyrecognized as occurring inCosta Rica. It has been suggested recent1y that /. cencho;z is actuany a composite oí two species,l. cenchoa and /. gemmis­ tratus. AnaIysis of data on scalation and coloration rOl Costa Rican samples confmns that this complex is comprised oC two species. One oC these is clearly the wide-ranging l. cenchoo. which in Costa Rica occurs in the SIOuthwest Pacific Lowlands, Meseta Central, Atlantic lowlands and cordilleran slopes and just on to the Pacific s1f\pe in the northem mountains. It does not range into the northwestem (Pacific) lowIands. A second species OCCUIS on the northwestem Pacific lowlands and in sympatry with cenchoa on the Meseta Central and at scattered localities in the Atlantic and southwest Pacific lowIands. The second form is anopatric to Pana· maniangemmistratus and consistently differs from the latter in scalation. A review of other Centrai American and Mexican samples referred to l. gemmistratus (type locality : El Salvador: Sonsonate : near Volean de Izal· (0) indicates that Costa Rican examples are conspecific with it. TIte species appears to be comprised of three aDopatric subpopulations along the Pacific versant: El Salvador-Honduras; Nicaragua...costa Rica; and Pana· má. A fourth more or less allopatric subpopulation occurs on the Atlantic versant of Costa Rica as well. The systematic status of allopatric eastem México and Yucatán Peninsula populations referred by recent authors to gemmistratus is problematic. Other allopatric Isthmus of Tehuantepec and western México po­ pulations seem more likely candidates to be conspecific with gemmistratus, but the issue cannot be resolved on the basis of available data. Attention is caDed to a unique unicolor variant of gemmistratus from Pacífic versant Costa Rica. lm antodes inornatus and cenchoa are restricted to evergreen- forest habitats. while gemmistratus is most abundant in deciduous forests along the west coast of Central America and Mexico. The latter species is sometimes found at evergreen forest sites on the Atlantic versants of Costa Rica and Central Panama. l. cenchoa and gemmistratus are known to be sympatric at severa1 sites in Costa Rica but not l. inornatus and the Iatter species. /. cenchoa and inornatus are often taken together.

The blunt-headed vine soakes, genus Iman­ small dark spots and speckles, that often form todes, fonn a oonspicuous component of the very narrow obscure crosslines. Segmental lowland and premontane forest of Costa Rica. counts for tms form are low: ventrals 199-2 18 Sorne twenty years ago we noted unexpected in males, 196-212 in female s; sub caudals 110· variation in characteristics of scalation and oo· 132; ventrals plus caudals 316-334. All other loration utilized elsewhere/ for distinguishing examples from Cqsta Rica were regarded as re· arnong nominal species and a consistent geogra· presenting the specie s Imantades cenchaa, phic variation in coloration that together raised wmch usually has a series of 31-73 dark brown que stions regarding the status of vine snake po· saddle s on the body, more than 223 ventrals pulations in the Republic. With the accumu· and ventrals plus caudals more than 350. latjan of additional materials. we concluded Within the series referred to the latter from, that the observed variation could best be inter­ samples from northwest to west-central Costa preted by the recognition of two species for Rica are markedly paler in dorsal ground and Costa Rica. (Scott, 1969; 1983; Savage, 1973; blotch colors than those from the Atlantic ver­ 1980). sant or southwestern Pacific Costa Rica. This One of these, Irnantodes inornatus, is a yel- color difference appears to be correlated with 10wish to light brown snake with a pattern of relatively narrOW vertebral scales and high body blotch counts, features attributed to Imantade, to separate Panamanian cenchoa from gemmis­ gemmistratus (Taylor, 1951; 1954; Peters and tratus. Orejas-Miranda, 1970)_ However !he segmental Aeeording to Myers' data (J 982), the latter COWltS for these snakes are mueh higher than two forms may be distinguished as follows: in found in putative upper Central America or Pa­ Panama. In this report variation is either indi­ nama gemmistratus. OUT samples sugge sted a ealed by the range or a notation sueh as 23- north-south cJine in Paeifie Costa Rica grading 29.4-39, where the first-number is the mi­ into the mueh higher count populations of nimum, the second the mean and the third the southwestern Costa Rica and adjacent Panarna, maximum for a particular sample: that appeared to represent typical cenchoa. For these reasons and the faet that the vertebral ",ncho. scale rows showed eonsiderably greater va­ riatian in width than had been previously re­ l. Scales in vertebral row conspicuously en­ ported, we regarded alJ Costa Riean material as larged, usually 3-4 times wider than lateral representing a single form,l.cenchoQ. This view scales. is refleeted in previous publications (Savage, 1973; 1976; 1980) and more fully explained by 2. Ventrals in males 244-288, in females 228- Scott (J 983). 268. RecentIy, C.W. Myers (J 982) in a masterful 3. Subcaudal s 147-195. review of the genus in Panama, has questioned oue conc1usions, sinee lmantodes cenchoa and 4. Ventrals plus subcaudals 405-446. gemmistratus¡ seem to be valid and distinctive iri Panama and South Ameriea where they 5. Body blotches 29-56. oceur in sympatry. Myers also refees to a num­ ber of individuals from widely scattered local· 6. Maxillary teeth 11·12.4·14 + 2. lities in Costa Rica, that he regarded as repre­ senting the latter form , although he did not un· 7. Total length to 1211 mm in males, 1480' in dertake a detailed revision of non-Panamanian females. material. Since Myers' work provides a campa­ rative baseline of data foc the two nominal 8. Tail length 26-34% of total length. speciOs and a eonflieting hyporhesis on the sys· 9. Hemipenes slightly clavate and slender; tematic status of the Imantodes placed in cen­ ealyeulate eapirulum 32-45% of sulcate side; chaa by US, and because extensive additional asulcate side thickly spinose below apex. material from Costa Rica has been collected since our previous study, we have undertaken a gernmistratus review of the problem. Essential1y the present paper addresses the following question: do one l. Seales in vertebral row slightly enlarged, or two species of Imalllodes in addition to l. usually 1.5·2.0 times wider than lateral inornatus occur in Costa Rica? scales.

2. Ventrals in males 227-235, in females 22 1· ANALYSIS OF CHARACTERS 228. 3. Subeaudals 113-130. Previous workers on the genus (Smith, 1942; Zweifel, 1959; Myers, 1982; and Yingling, 4. Ventrals plus subeaudals 341·361. 1972) have emphasized a small suite of variable characteristics to discriminate among nominal 5. Body blotehes 55-74. forms. These include : the relative size of the enJarged vertebral scales; segmental counts; and 6. Maxillary teeth 10-10.8-12 + 2. eoloration, partieularly the number of body blotehes or saddles and how many of these are 7. Total lenghth to 693 mm in males 786 mm broken off late rally to form discrete dark spots. in females. Myers (1982) also utilized differenees in size and proportions, maxillary teeth and hemipenes 8. Tail lenght 24·28% of total length. SA VA GE & SCOTF: lmantodes of Costa Rica 109

9. Hemipenes shorl and stubby; calyculale Pacific area and most Atlantic specimens have capilulum. 50% of sulcale side; asulcate side the vertebral scale rows greatly expanded (3-5 sparsely spinose lo lip. times the widlh of Ihe laleral scales). In Ihe up­ land Meseta Cenlral and at scattered Atlantic The fo llowing analysis deals primarily wilh versant 10caJities, both narrow and expended characters 1-5. While characlers 6-9 may be vertebral scale rows were fo und in individuals helpful in allocaling parlicular individuals lo that approach one another in other characters. one or another nominal fo rm, the limited num­ It was partially for íhis reason that we con­ ber of mature males restricts the use of feature duded earJier (SCOlt, 1969 ; 1983; Savage , 9 and Ihe varialion in Ihe olhers predudes Iheir 1973; 1980) Ihat onJy cenchaa occurred in Cos­ use as major criteria in recognizing popula­ ta Rica, Ihat Ihis feature was unreliable in at­ tions. Allhough Ihe presenl sludy is airned tempting to separate populalions within Ihe primrily al delermining Ihe stalus of snakes genus, and that gemmistratus should be exclud­ referrable to the cenchoa - gemmistratus ed from any listing of Ihe Costa Rican snake complex , appropriate comments on variation fauna. in inomatus are includes. SeimentaI rounts: In cornmon with most Vertebral scales: The vertebral scale row i, snakes, Imantades exhi1tits sexual dimorphism slightly lO greatly widened as compared lo Ihe in the segmental scale counts. Unlike most laleral scales in Ima ntades. Smilh (1942) re­ olher sexually dimorphic snakes, Ihe males of cognized three categories of vertebral enlar­ Imantades average a higher number of ventrals gemenl for Ihe genus: a) nol or very slightly (V) Ihan are fo und in females, ralher Ihan the wider Ihan laleral scales: b) aboul Iwice as wide converse. As in other sexually dimorphic gene­ as lateral scales and; e) three to four times as ra, the males average a higher nUmber of sub­ wide as lalerals, and partially on thal basis re­ caudals (SC) than are found in femaJes_ In cognized six Mexican species in the genus. Pe­ lm antodes inornatus, males average about 7 lers (1954) showed Ihal Ihe variation in verte­ more ventrals than females and 8 more sub­ bral scale width between Smith's categories a caudals. In defmitive Imantades cenchoa from and b was bridged in Ihis malerial from western Panama (Myers, 1982) males average 10-13 Mexico and concluded Ihal Ihe nominal species more ventrals Ihan females in six geographic splendida was conspecific wilh Cenlral Amer­ subsamples and 7-22 more subcaudals. Diffe ­ ican gemmistratus. Zweifel (1959) reduced Ihe rences similar to those found in the latter are number further by placing alI named popu­ also characteristic of individuaIs referred to lations (except cenchoa and tenuissimus of the lmantodes gemmistratus by Myers and for our Yucalan Peninsula) in gemmistratus by show­ Costa Rican samples. ing intergradation in segmental counts and co­ The range of variation in segmental counts, loration among them. which appears lo provide Ihe most useful dis­ Myers (1982) ulilized Ihis fe ature lo dis­ tinguishing character for separating the nominal linguish Panama cenchoa (3-4 limes as wide as fo rms in Panama. showsconsiderable overlap in lalerals) from gemmistratus (usually aboul Ihe two sexes. This is especially Ihe case for the 1.5-2 limes as wide), allhough he observed sub caudal counts in Iwo species (158-195 in Ihal Ihere was much grealer variabilily in Ihe males and 147-177 in female cenchaa; 116-1 32 fealure Ihan previously realized. in male and 110-122 in female inarnarus). In The widlh of Ihe verlebrals in our samples Ihe relatively small sample (N = 19) of gellllllis­ varies 1.2-5 limes Ihe widlh of Ihe mid-Ialeral tratus from Panama discussed by Myers, the scales near mid-body . In lm antodes inomatus, sub caudal ranges of Ihe Iwo sexes barely over­ Ihe vertebral scale rows are consislently 1.5-2 lap (males 124-130, females 113-124). For t his times wider Ihan Ihe mid-Ialeral scales. The size reason the range of sub caudal counts. without of Ihese scales shows a slrong correlalion wilh regard to sexo may be used to distinguish geography and Ihe characlerislics of segmenlal cenchoa from inornatus and gemmistratus and body blotch counls. Malerials from north­ (See number 3 above)_ Sirnilarly Ihe 10lal seg­ westem Costa Rica have consistently narrow mental counls (ventrals plus subcaudals) . vertebral scales (1.2-2.5 Ihe widlh of the laleral wilhout regard to sex, pro vide a complete se­ scales) while most of those from the southwest paration of the Ihree nominal forrnsin Pan ama with ranges of 405-446, 341·361 , 316·334, for have rnediurn brown interspacesor the suffusion cenchoa, gemmistratus and inornatus, res­ of the in te rspace s by dark pigment produces a pectively. medium brown tone. Most individuals from the As an ínitial attempt to a�rtain if more than northwest and Central Pacific lowlands and one form of the cenchoa-gemmistratus complex Meseta Central Occidental are very pale and of· might be represented in available Costa Rican ten have a distinet yellow-gold cast. material, we analyzed Ihe data for subcaudal The typieal coloration..of the cenchoa-gem· and ventral plus sub caudal eounts. Sub· misrratus complex almost always iocludes a caudals vary between 129·183, in examples series of dark blotehes, saddles or bands along with complete tails and Ihe total segmental the length of the body and tail. Usually the counts from 358-459. These counts strongly blotches narrow toward the venter and fre­ suggest that only one of Ihe forms (cenchoa) quently many of the posterior saddles 01 bands reeognized by Myers (1982) as oeeurring in Pa· have the lower portion broken off to form a nama is included wilhin the Costa Riean diserete lateral spot on one or both sides. Three sample. since the known variation foc Panarna general patterns may be reeognized as follow cenchaa is encompassed by these values. (Fig. 1): Unfortunately the clear separation of cenchaa from gemmistratus on the basis of sub­ A. large ehestnut brown blotches or saddles caudal and total segmental counts seen in Pana B. relatively narrow light brown blotehes or ma does not hold in Costa Rican materiaL A bands number of examples have sub caudal counts C. relatively narrow rnedium brown bIot­ intennediate in value in a range between 130- ches or bands, with a distinet light spot in 147, and many have total segmental eounts the center; on the posterior part of the between 361-405.This variation and our belief body Ihe blotehes are roughly diamong. that !he vertebral seale eharaeter failed to con· shaped and form definite light·eentered sistently separate samples, led to our earlier oceUi. conclusion that only a single rather variable species of this stock occurred in Costa Rica. rhe blotches or bands are in most cases out­ lined by dark brown to black. Blotches in in· Coloration: Severa! features of coloration dividuals having lhe A pattern are uniforrnly exhibit variatíon in the cenchoa-gemmistratus reddish brown (chestnut) and juveniles with complex (the coloration for l. inornarus has Ihis bloteh pattern have blotehes that are al· already been deseribed above). The dorsal most red In a few individuals two or more ground color in Costa Rican samples is pale tan dorsal blotehes are fused into an irregularly or beige to medium brown. In many individuals shaped sinuous figure that forms a zig-zag stripe the ground color is heavUy suffused with dark along short segments of the body.ln other brown pigment (Fig. I A) so that the interspaces examples a single large bloteh may be broken between the very dark brown blotches or sad­ up into two small roundish blotehes. Sorne· dles are darkened and the snake has an overall times a series of several botches on the posterior dark appearance (darkened ground color). In third of the body may be broken up in Ihis other individuals the tan interspaces (and dark manner to orm a conlinuous row of small blotches) are mueh lighter (Fig. lB) and the spots. In the latter cases lhe equivalent number entire animal often has a distinct yellowish cast of large blotehes can be determined by eount· (pale and/or yellowiseh ground color). Other ing the lateral spots, which do nOl show a com­ examples are somewhat interrnediate between parable fragmentation. Usually , there are two these two extremes and have the interspaces small dorsal blotehes for eaeh lateral spot in medium brown or suffused with medium brown these examples. pigment (medium brown ground color). The splitting of blotehes in the manner des· rhe is sorne geographic consistency in cribed above affe ets the total body blotch ground color, with most examples from south­ (BB) eounts. For Ihis reason, in the tex!. re· westem Paeifie lowland Costa Rica having the fe rence is sometimes made to the number of most darkened ground color, followed by blotch positions when comparing individuals. speeirnens from the uplands of northern Costa The number of bloteh positions is determined Rica. The snakes from the Atlantie lowlands by summing the number of blotches Ihat ex· A B e

Fig. 1. Pattenrs of dorsal blotching inlm.ontodes. tend late rally to or almost to the venter and the the Pacific coast and suggests Ihat both of the number of discrete lateral blotches found on forms recognized from Panaroa also occur in !he posterior part of the body. This number Costa Rica. compensates for the fragrnentation of Qne to A more detailed analysis indicates Ihat Ihe several posterior body blotches into small majority of available specimens from Costa spots, Ihat raise the body blotch count. For Rica have low numbers of body blotches vary­ example , one specimen (CRE 3041) has 50 dor­ ing from 33-50. Snakes wilh this range of va­ sal body blotches, with four posterior ones very riation are found along the Atlantic versant, in small. The number of blotch positions is 48 and the southwest Pacific lowlands and in sorne the higher number seems to have beeo pro­ upland areas. Imantades wilh higher body duced by the division of two larger blotches to blotch counts occur along Ihe northwest Pa­ produce four small ones. The use of body cific lowlands, on Ihe Meseta Central and at blotch positions also compensates for fus ions scattered localities on the AtIantic versant and among blotches as well. in south-westem Costa Rica. This pattero The number of dark body blotches appears of variation also influenced our earlier decision to show no sexual dimorphism in lower Central to regard the high blotch number snakes as America and Myers (I 982) recorded only slight representing part of a continium within a overlap between cenchoa (29-44. 2-56) and single species. gemmistratus (55-74) in Panarna. The number The number of posterior body blotche, with of dorsal body blotches for available specimens the lower portian broken off to forro lateral of the complex from Costa Rica ranges from 'pot, (BBB) wa, shown by Smith (1942) to 31-73, excluding a single unblotched individual have sorne consistent geographic variatian. (CRE 8261) from La Julieta near Parrita, on Myers (1982) denmon,trated Ihat Ihi, feature had much greater variability Ihan imagined by There is no overlap between Panama gemmis­ Smith as amply reaflJf1Jled by Costa Rican ma­ tratus and Ihese snakes in ventral, sllbcaudal or teraL In the latter sample the counts for Ihis ventral plus subcaudal counts. The northwest fe ature vary hetween0-39_ Very low counts are Costa Rican specimens do not seem to represent typical of Ihe soulhwest Pacific series (0-3) cenchoa because of the size of the vertebral and high counts (23-39) for norlhwest Pacific scalesand Ihe differencesin coloration(cenchoa specirnens. lntennediate values occur at mast haspattem type A, see Fig, lA) and numberof other sites_ sub caudal scales (146-195). There is however considerable overlap in ventral and ventral plus sub caudal counts and a slight overlap in body RE-EVALUATlON OF THE PROBLEM blotch numbers. between cenchoa and this sample. Apparently, the northwestern Costa Ri­ The complex geography, physiography and can Imantodes represent a single species not climate of Costa Rica and our impression that identical with cenchoa and not c1early identical there was a corresponding complexity of va­ with Panama gemmistratus. Consequently, this riation and relationships among samples of form will be designated "species A" for the re­ lmantodes, led us to center the initial stages of mainder of this analysis and for eomparison Ihe re-analysis on small to moderate sized geo­ with other samples. graphic areas_ Our thinking was Ihat once the The southwestern lowland area of Costa Ri­ smaller subsets of Ihe samples were understood ca centered on the Golfo Dulce, is a region of Ihey could be linked into a wider geographic high annua! precipitation and a very short dry context and compared with forms recognized season (December to February or March). The elsewhere in Central America and Panama_ For blunt-headed vine snakes from the region these reasons the following sections treat around the Río Grande de Térraba southward, /nuzntodes of the cenchoa-gemmistratus lineage a1so form a very homogenous sample with two in Costa Rica according to geographicregion as exceptions that will be treated later. This sam­ foUows: 1)_ Pacific lowlands (northwestern Cos­ pIe is characterized as follo ws: (1) vertebral ta Rica; southewestem Costa Rica; intermediate scales 3-5 times a wide as lateral scales; (2) sites); 2) Upland areas (slopesof the Cordilleras ventrals in males 258-278, in fe males 246-274; de Guanacaste and Tilarán ; slopes of the Cordi­ (3) subcaudals in IÍlales 156-183, in females llera Central and MesetaCentral) ; and 3) Atlan­ 149-179; (4) ventrals plus subcaudals 406· tic lowlands and foothills_ 459; (5) body blotehes 31-43;(6) broken body blotches O - 3; (7) ground color heavily suffused with dark pigment to produce a very dark ap­ The Pacif'IC Lowland._ The region of north­ pearance. west Costa Rica from the Nicaraguan border to There can be no question that this series the area around the mouth of the Ri0 Grande represents lmantodes cenchoa since it closely de Tárcoles exhibits a dermite wet season(June resembles the population referred to that form October) and a long dry one (November-April). from adjacent western Panama by Myers Specimens of Imantodes from the regioo seero (1982), although averaging slightly higher in to rorm a relatively homogenous sample segmental eounts. eharaeterized as follows: 1) vertebral seale A third small series of lmantodes from Pa­

rows 1.3-2.5 times as wide as lateral scales; (2) eifie lowland Costa Rica is fro m an interme· ventrals in males 244-249, in fe males 238-248; diate area between Quepos and the mouth of (3) subeaudals in males 138-147, in fe males the Río Grande de Tárcoles. Four of these 135·1 54; (4) ventrals plus subeaudals 376-404; examples (eRE 7139, 8255, 8261 , 8263) form (5) body blotehes 51-73, of types B and C Fig. the basis ror Scott's (1983) assertion that lB, e); (6) broJ

e Fig. 2. 1mantodes from western Costa Rica. A. Unusual uniform pattem (eRE 8261). B. Reduced posterior blotching (CRE 8263). C. Typical pattern C (CRE 7001). D. Pale pattern C (CRE 7139). The bar equals 4 cm. The extremely unusual coloration of two of 1ese snakes requires further cornment since B). The most bizarre pattem occurs in eRE 1ey rival the unique striped condiÚon found in 8261 , which is without any suggestion of dark NO specimens of the Amazonian Imantades blotches on Ihe body or tall. The ground color mtiferus (Myers, 1982), as extreme variants in is uniform beige with a sJight yellowish cast and ,ese normaJIy dark blotched fo rms (Fig. 2A, the entire upper surface is punctated with dark SAVA GE d: SC01T: lmantodes of Costa Rica 115

pigment that is concentrated a10ng the scale northwest Costa Rica ("species A") and one matgins. Under magnification eaeh scale has the in soulhwest Costa Rica, that may be consist­ punctations concentrated to form a darked out­ ently distinguished on the basis of the amount line arotind lhe light center. Over most of the of vertebral scale enlargement, color pattem, body amI tail the enlarged vertebral scales a1so number of body blotehes and ventrals plus sub­ show this tendency to produce an obscure light caudals. They further differ in ventral and sub­ vertebral stripe. The head has a dull dark com­ caudal counts a1thousl!. lhere is sorne overlap, plex marking above; the venter is light but with lhe soulhwest Pacific species having higher punctated with dark brown, particularly la­ counts for all segmental characters. The latter terally. fo rm is conspecific with Imantodes cenchoa CRE 8263 is somewhat intermediate be­ while the former approaehes Panama Imantodes tween the specimen described above and gemmistratus. but -i, completely distinct from blotched examples from the area. The dorsal lhat population in havint, much higher seg­ ground color is similar to that for CRE 8261 mental counts (Y, SC and Y+SC, see Tab. 2). A but anteriorly it has 31 distinct dorsal and 17 second gemmistratus�ike series_ of female lateral blotches. Posterior to lhis point on the snakes from localities intermediate between body lhe dorsal blotches are represented at best (Pozo Azul-Parrita) the samplesdiscussed above by small dark spots and the lateral .spots are si­ have somewhat lower segmental counts than milarly reduced. In terms of blotch position , found in "species A" J as do the two males from there appear to be around 50 positions and within the range of southwest Pacific cenchoa. about 39 lateral spots.Except for the very faint These examples approach Panamagemmislratus suggestion of spots the posterior coloration of in segmental counts but are completely separat­ this individual is identical to lhe uniform in­ ed from them in total segmenta! counts, when dividual described above. the sexes are compared separately. This sample Two olher examples, both males, of gem­ of seven individuals is therefore somewhat mistTatus-like snakes have recently been disco- , intermediate between Panama gemmistratus vered from the southweslern Pacific lowland and "species A" . area and have been called to our attention by Uplaod Aleas: A. NQrthwest upland series: Douglas C. Robinson. Their salient features in A sample of 14 snakes from the Cordilleras de addition to having the vertebral scale row less Guanacaste and Tilarán from sites between than two times the width of the lateral scales, (480-1500m), is comprised of 12 individuals a type C color pa ttem and the dorsal ground with enlarged vertebral scales, high sub caudal color light brown include: counts (149-175) and body blotches of type A, ranging in number from 35-52. The upper limit Coto Bros: v SC V+SC BB of the range for the latter feature is represented VCR 3401 241 141 382 53 by a male (CRE 4461 from near Monteverde, Quebrada Leona: VCR 6929 244 144 388 49 Provincia de Puntarenas 1400 m) with 45 blotch posilions in which seven blotches includ­ These examples have higher ventra , sub­ ing the last three are broken into two small caudal and vent ral plus sub-caudal couníls than spots. These snakes,are lmantodes cenchoa. Panam> male gemmistratus (227 - 237,; 124 - Two other examples, both females, have re­ 130; and 357 - 361 , respeetively). They r�semble latively small vertebral scales, slightly lower ··species A" from northwest Costa Rica ip those subcaudal counts (145-146), lack the type A regards, but tend to be near the lowe� límits color pattern and have 51-55 body blotches. ln of each range for that formo Sin ce males have these features and all other regards these spe­ more ventrals and sub caudal s than fe males in cimens (UCR 4650 and UMMZ 131406) re· Imantudes. the se two examples abo resemble semble very closely "species A", the gemmis­ lhe Jacó - Parrita snakes (all females) discussed tratus-lilie form, from the adjacent northwest above, when allowance is made for sexual di­ Pacific lowlands. Both examples are from near morphism, and set:;m to represent the same Tilarán, (from I km NW Tilarán and Los Ange­ species. les, about 6 km NW of Tilarán, respectively) The silualion for the Padic lowlands may where indisputable cenchoa occurs in virtual be summarized as fo llows: there are· two dis­ sympatry. A comparison of these two snakes tinetive apparently allopatrie forms, one in to others from the area follows: 116 REVISTA DE DIOLOGIA TROPICAL

V SC V+SC DD B. Meseta Central series: Myers (1982) in bn NW nIarin: I strainghtening out lbe identifications for the UCR 4650 231 145 386 55 Los An¡¡eIes type specimens of several of Cope's.names for UMMZ 131406 239 146 385 51 Imantodes based upon Costa Rican examples, reamed the conc;Iusion that a number were conspecific with Imantodes gemmistratu. as amchoa diagnosed in Panama. He challenged the idea (Scott 1969; 1983; Savage 1973, 1980) that V SC V+SC DB only one species of the cenchoa - gemmistratus ElSilencio: oomplex occurred in Costa Rica on this basis CRE62I8 253 169 422 43 but did nOl undertake a full analysis of lbe CRE6222 244 154 398 41 problem. In particular he reoognized Cope's SanDo"",: (1894) types of Himantodes semifascÍlltu. as CRE 6277 257 165 422 35 gemmistTatus. nIarin: representing The specimens are UCR 6134 259 166 425 labeled Pozo Azul (AMNH 17314), with UMMZ 126716 257 163 420 40 locality data erroneously transliterated to Paso Azul and from "Alajuela" (AMNH 17356), A juvenile cenchoa (CRE 3621 from 2.2 km Monte Aguacate (AMNH 17330 - 31) and San E of Los Angeles), with 43 body blotches, for José (AMNH 17296-97, 17355) (see Savage, wltich segmenta! counts could not be made be­ 1974 and below). Another type of semifa scÍll­ cause of its condition, further conrmns that tus from Santa Clara, Provincia de Limon two sympatric species occur in this zone . (AMNH 17273) was later made the holotype 1be two gemmistratw·like snakes from the of a new species, Himantodes hemigeniu. by lilarán area seem to represent lbe same forro as Cope (1899) and will be discussed later in tltis fo und in lbe northwest lowland area of Costa pape". lhe remaining types of semifascÍIltus, Rica. For this reason lbey are incIuded with incIuding the example designated as the lecto­ lbat sample as part of species A in subsequent type (AMNH 17357) of lbe name by Myers discussions. (1982) and lbe holotype of Himantodes aniso­ lmantade. cenchoa from these uplands have lepsi. Cope, 1894 (AMNH 17274) from Monte significantly lower segmental couns lban the Aguacate were regarded as cenchoa, conclusions population from the southwest Pacific low­ wilb which we conc()r. lhe other syntypes are lands (Table 1). In this regard there is an ap­ from Carrillo, Provincia de San José (AMNH proach to the northwest Pacific lowland 17357), and Sipurio , Provincia de Limón "species A" in lbe upland samples of cenchoa (AMNH 17358), with it s locality data erro­ from tltis region, which led Scott (1983) to neously transliterated to Sapurio , (see Savage, concIude that intergradation between the two 1974 and below). fo rros occurs on the Pacific slope of the Cordi­ The example from Pozo Azul, Cantón de llera de Guanacaste . lhe data presented above Acosta, Provincia de San José, (incorrectly list­ show that the two species occur sympatricaIly ed as Provincia de Puntarenas, Cantón Aguirre along the slopes of the Cordillera de lilarán and by Savage, 1974) has been discussed above the only two available specimensfrom lbe Gua­ with other lowland Pacific versant examples. nacaste range confrrffi this conclusion. 80th lhe remainder of the Cope material reviewed examples (KU 31946, a male and KU 34034, by Myers (1982) suggests that two species a female) are typical cenchoa in the vertebral occur in the upland Meseta Central area, and seale enlargement , color pattem type A with 41 are sympatric at least in the Monte del Aguaca­ (40) blotches and 45 body blotches (there are te, Provincia de Alajuela (1000 m). One of 41 blotch positions but two blotches are fused these forms íscenchoa and the other isgemmis­ together) and 14 and 16 broken body blotches, tratu., acoording to Myers. respectively. In addition the segmental counts Data for 28 examples of Imantodes from the are : ventrals 246, 236; subcaudals 175, 149; Meseta Central (Pacific drainage) and two from ventrals plus subcaudals 421, 385, respectively . the Meseta Central (Atlantic drainage) seem to Examples from the southern portion of the clarify the general problem and elucidate lbe Cordillera de Tilarán near Monteverde are all relationship between species A from the Pacific unque stionable cenchoa. northwest and other gemmistratus·like popu- SA VA GE el SCOTT: lmantodes of Costa Rica 117

lations. Only fl Ve of the snakes from the Meseta Pacifie Panama Costa Rica appear to represent cenchoa. They are from Montes de Aguacate (AMNH 17274), the city Subdaudals of San José (NHMW 25472.1, ZMH RO 1980); Ó 137-147 124-130 and Navarro (UMMZ 74304) and Azahar, Pro­ 9 129-154 113-124 vincia de Cartago (NHMW 25528.1). All other Ventrals plus material has reduced vertebral scale rows, pat­ Subcaudals tem types B or C and relatively low ventral plus Ó 373404 357-361 subcaudal counts (360 - 389). 9 358401 341-345 The latter series of 24 individuals has the fol­ lowing features: 1) vertebral scale rows 1.3 - 2.1 times as wide as latera! scales; 2) ventrals in males 233-246, in females 229 - 240; 3) sub­ Within the Costa Rican series the Meseta caudals in males 137 - 146, in females 130 - 138 Central specimens are essentially intermediate 4) ventrals plus caudals in males 373 - 389; in between southwest and northwest samples in females 360 - 378; 5) body blotches 41-61 of segmental counts, although having substantially types B and C (Fib. lB, C); 6) broken body Iower maximum values for each Count when blotches 8-34; 7) dorsal ground color light compared to the latter and resembling the for brown, often with a yellowsih casto mer rather closely in variational range . This sample obviously resembles, the Pana­ ma gemmistratus . "species A" from northwest It seems, therefore , that all upland and Costa Rica and the ambiguous gemmistratus­ lowland Pacific versant gemmlstratus-like sam­ like specimens from southwestem Pacific low­ pIes are conspecific with one another and land areas. The former may be separated from "species A" of northwest Costa Rica. Whether Ihesegemmistratu s-like samples as follows: they are conspecific with the species called gemmistratus in Panama by Myers (I982) is Panama SW Paeifie Meseta NW Paeifie unknown. The relatively high ventral and ventral plus Ventrals sub caudal counts for the Meseta examples Ó 227-237 241-244 233-246 244-249 available previous to the present study led 9 221-228 226-242 229-252 238-248 Scott (I983) to regard them as showing inter­ gradation between cenchoa and gemmistratus­ Subcaudals like populations on the Meseta Central. AI­ Ó 124-130 141-144 137-146 138-147 though the considerable variation in cenchoa 9 113-124 129-147 130-150 135-154 in this area also contributed to this conclusion. nothing in the present study substantiates that view. Ventrals plus Subcaudals The remaining Meseta Central specimens Ó 357-361 382-388 373-389 382404 previously referred to Imantodes cenchoa are 9 341-345 358-389 360-382 376401 discussed in the context of the following sec­ tion.

These data show that the' three Co�ta Rican C. La Palma-La Hondura sample : three samples resemble one another more c10sely snakes (CRE 7144, UCR 4316-17) from the than any one of them resembles the snakes pass between La Palma on the slope north of from Panama. AH Costa Rica samples have the Meseta Central Occidental to La Hondura higher counts in each category than do the Pa­ on the Atlantic slope, are typical cenchoa and nama example s. While there is some overlap in agree c10sely with one another in all fe atures. venlral counts among the four series, Costa Ri· They may best be compared with Meseta Cen­ can specimens consistently have much higher tral individuals of that form as a basis for sub­ sub caudal and ventral plus sub caudal counts for sequently determining ·the populational affin­ the same sex than occur in Panama, as is shown ities of all lO examples (no counts were taken below : for ZMH RO 1980 because of its condition): TABLE l

Geol'ophic variation in CoIto Rica: lmantOOescenchoa

Vent:rals Broken + Body Body N Ventrals Subcaudal. Subcaudals Blotches Blotches Pacific <1 12 258-270.7-278 156-175-183 432-447.1-459 35-39-41 G-O.2-3 9 10 246-256.6-274 149-165-179 406-423.1-453 31-38.2-43 O

NW Uplands <1 7 23J-249.6-259 165-167.6-175 420-422-425 35-42.1-52 12-14.4-17 9 3 236-238.7-244 149-152.J-154 385-391-398 41-42.7-45 14-17-21 undet. 1 43 12

Atlantic and Central uplands <1 34 235-249.5-269 147-166.2-180 38J-416.6-442 3J-43.7-51 2-13.6-19 9 26 228-240.6-245 146-158.4-168 39()'399_6-411 32-43_5-49 ()'15.J-27 undet. 13 228-242.4-259 145-157.6-176 385-398.8-431 37-42.J-47 16-16.7-19

TABLE 2

Geographic variatían in Imantodes gemmistratus-like mmpkl from Cofta Rica ond PONZmll

Ventrals Broken Plus Body Body N Ventrals Subcaudals Subcaudals Blotches Blotcltes

NW Pacific <1 6 244-246.8-249 138-145.8-147 382-393_J-404 56-65_8-73 24-30_4-39 9 11 238-242.3-248 135-144.8-154 376-388.1-401 51-57.8-66 2J-28.1-34 undet. 2 238-244.5-25 1 144-144.5-145 382-389-396 62-6J-64

SW Pacific <1 2 241-242.5-244 141-142.5-145 382-385-388 49-51-53 8 9 5 226-234-242 129-135.2-147 358-369.2-389 (0)52-55-64 (0)29-34.7-39

Meseta <1 14 23J-24O-246 137-142.8-146 373-382.4-389 41-53_2-61 8-23.6-34 9 8 229-233.2-252 13()'135.1-150 36()'366.9-382 46-52-56 14 undet. 1 241 139 380 51

Atlantic <1 4 231-236-241 139-142.H45 37J-378.6-386 54-55-56 21-24-27 9 8 225-236-242 134-140.1-144 358-373.6-382 47-52-59 14-24.J-33 undet. 1 143 159 383 49 PANAMA

<1 9 227-232.9-237 124-126.130 357-361 9 11 221-225.2-228 113-118.124 341-345 55-74 s.tVA GE <1 SC01T: ¡""""ad., of Costa Rica 119

v C V+C BB BBB Monte del A3uacate AMNH 17274 d 270 173 443 39 o

San Jo..! NHMW 25472.1 d 250 171 421 48 14

úh1ma: CRE7144 d 236 147 383 40 14

LaHondura: UCR4316 232 153 385 41

V SC V+SC BD BBB

UCR4311 240 147 387 42

UCR 2052 d 248 153 401 44

UCR 2053 d 243 159 402 42

AzaIIar: NHMW 25528.1 d 241 158 399 32 9

NDuro:

UKIoIZ74304 d 236

These data soasest ronsideable differences The specimen from San José city does he_ cenclwa populations at Ibe westem not fit readily wilb either the southwest PaciCic edge of the Meseta Central (Montes del Aguaca­ series or with other upland examples. The seg­ te), at San José and on the slopes to the north mental counts are high when rompared to the and eas! toward !he At1antic versant. The Mon­ latter, but Ibe presence of 14 body blotches tes del Aguacate specimen agrees in alI parti­ Ibat have broken off lateral spots separates it culars(Table 2) witb the soulbwest Pacific low­ from Ibe forroer, which usually has no lateral land SlIIIple of Ibisforro and differs from other spoto at alI (maximum of 3 in one specimen) . samples in having higher segmenta! rounts. For The status of tbis example will also be discus­ Ibis reason it has been included witb the low­ ed below in relation to the analysis of A tlantic land Pacific population in subsequent discus­ lowland samples. lt further confirms Ibe vir­ sions and Ibe tabulation (Table 2) of geographic tual sympatry of lmantodes cenchoa and "spe­ variation. Too specimen confmns Ibe virtual cies A" since both have now been examined sympally of cenchoa and "species .A" at a se­ from the city of San José. rond location along the Pacific slope of Costa Rica. The Atlantic Lowlands and Foolbills: The The material from Ibe La Palma pass area Atlantic lowland and foothill zone of Costa Ri­ and the upper Río Revenlazón valley south of ca originally supported a continuous broad­ Cartago on the A tlantic portion of the Meseta leafed evergreen forest because of the extended Central, closely resemble one another. They rainy season, interrupted by a bríef two month diCfer markedly from southwest Pacific lowland dry period in Januar, February and March. Two cenchoa in having lower segmentaljcounts and distinctive forros of lmantodes of the cenchoa­ more numerous lateral body blotches. Of the gemmistratus complex occur in sympatry at so­ samples discussed to this point they resemble rne localities on the Atlantic versant of Costa those from Ibe uplands of northwestem Costa Rica. By far the most abundant is a spedes with Rica (see previous section). They also approach greatly enlarged vertebral scale rows, color pat­ examples of cenchoa from the Atlantic low­ tem type A (Fig. lA) and a relative low num­ lands and for this reason their fi nal allocation ber of dark body blotches (33-50). Although willbe mentioned below. Ibis population has fewer ventral. than cenchoa 'rom southwest Pacific Costa Rica (Table 1) males, 134-150 in females; 4) ventrals plus sub· rnd usually has sorne posterior, dorsal dark caudals 373-386 in males, 358-382 in females ,lotches broken late rally to form lateral spots, 5) body blotches 46-59, of pattem type B or C; .t closely resembles westem AUantic lowland 6) broken body blotches 14-34; 7) dorsal ?anama examples referred to ce'nchoa by Myers ground color medium to light' brown, sorne ) 982) and we have litUe doubt that only a examples with a yellow casto These snakes ;ingle wide-ranging species is involved. Because may be distinguished most.readUy from sympa· the ventral and the ventral plus subcaudal tric cenchoa by differenees in vertebral scale ::aunts are low in this population, these values row enlargement (1), color pattern type (5) )Verlap the upper limits ofvariation for the Pa· and less consistently in total segmental counts cific versant populations of "species A". The (4). several examples of this species from the upper Atlantic Costa Rica gemmistratus·like Imah· portions of the Meseta Central and surrounding todes are consistently separated from Panama­ slopes (discusses above) c10sely resemble the nian gemmistratus (Myers, 1982) by having AUanlic samples and probably the same po. much higher subcaudal and ventral plus sub· pulation. One of us (Scott, 1969, 1983) thought caudal counts, as follows: that this tendency suggested intergradation be· cenchoa gemmis· tween and "species A" (called Atlantlc tratus by him). As shown, this is not the case Panama Costa Rica sinee the two may be unequivocally separated Subcaudals and are sympatric at several locations 00 the d 124-130 139-145 9 113-124 134-144 Meseta Central Occidental. A similar situation occurs in the Cordillera de Tilarán where sym· Ventrals patry between cenchoa and "species A" is do· plus Subcaudals cumented in an earlier sectian of this papero d 357-361 373-386 lmantodes cenchoa of the northwestem 9 341-345 35l!-382 uplands resemble Atlantic lowland samples in having low segmental counts (Table 1) and This is nOl supnsmg sinee gemmislTatus m there is sorne overlap with the relatively high Panama is virtually limited to the Pacific slope, segmental counts found in the northwest Pa· with only a few central Panama records from cifie versant popuJation of "species A". We the Caríbbean drainaBe, sorne 350 km ESE have a1ready described the trenchant differen· from the nearest locality for gemmistratus·like ces between "species A" and cenchoa in the snakes in Costa Rica (CRE 3147; Pandora, Pro· area of verlap (see section 00 northwestern vincia de Limón) . For this reason it is even les.... upland samples) and have refuted Scott's suprising that the Atlantic lowland series from (1969, 1983) c1aim of intergradation. Costa Rica is virtually idenlical to the samples Costa Rican A tlantic lowland cenchoa may of series A from the Meseta Central and south· be consistently distinguished by the following west Pacific lowlands (Tab. 2). We have no features: 1) vertebral scale rows 3.2-5 times as hesitancy in referring these three series to a sin­ wide as lateral scales; 2) ventrals in males 235· gle form, although and sinee the Atlanlic suite 269, in females 228-245 ; 3) subcaudals 152- differs from the northwestem lowland spe· 180 in males, 146-168 in females; 4) ventrals cimens of "species A" in exactly the same ways plus subcaudals 393-442 in males, 390-411 in �nd degree as Mlseta and southwest samples females; 5) body blotches 33-50 of pattem type do. That the four series represent a single spe· A; 6) broken body blotches 0-27; 7) ground co· cies is evidenced by the similarity in vertebral lor tan to mediwn brown. scale row enlargement, color pattem, numbers Taylor (1951, 1954)and Myers (1982) both of dark body blotches and overlap in segmental reported Imantodes gemmistratus from Atlantic counts (Tab. 2). lowland Costa Rica. Our study has discovered 13 examples of gemmistratus·like snakes from this region. They may be characterized as THE COSTA RICA SITUATlON follow.: 1) vertebral .cale rows 1.5-1 .9 as wide as lateral scales; 2) ventrals in males 231-241, in The analysis of avallable material of Imanto· remales 225-252; 3) subcaudals 139·145 in des from Costa Rica confnms Ihe conclusions SA VA GE &- SCOTT: lmantodtl of Costa Rica 121

83

�--�------+------� II

101---'-..

9r---�-----t----i-----r-��

'3 I(ILOMETERS

A IMANTODES CENCHOA

-- I 500 M CONTOUR oo·�------L------�e�5�------L-----�ef.4.------L------J,�----�e

Fig. 3. Oistribution of lmantodes CBChoG in Costa Rica.

of Taylor (1951, 1954) and Myers (1982) thal Imantodes inomatus occurs in lowland and three spe cies occur in Ihe republic. One ofIhese, premontane evergreen fo resls from Atlanljc Imantades inornatus, is found in sympalry wilh drainage southem Nicaragua lo weslem Ecua­ Imantodes cenchoa al a number of localilies dor. In Costa Rica (Fig. 3) il is found alOIl& the and has never been confused with other mem· entire Atlanlic slope from near sea-Ievel lo 900 bers of the genus. The second spe cies is cen­ m, in the uplands of the Cordillera de TilaItn choa, which has a wide geographic distribution lO 1450 m, and on the southwest Pacific low­ is evergreen forest situations from southem lands and slopes lo 1200 m. lt exlends south­ Veracruz on Ihe east coast and Chiapas on the ward on both coasts of Panama and throu¡h west coast in Mexico ; to Argentina. A third weslem Colombia no weslem Ecuador. form (referred lo above as "species A") called Imantodes cenchoa probably has a· oontin­ gemmistratus by Taylor (loe. cil), was Ihought uous range along the Atlanlic versanl from Ve­ lo be conspecific with Pan.manian malerial re­ racruz, Mexico, Ihrough Central Amcrica, ferred lo that fo mi by Myers (loe. cit .). Tbis aIlhough only a few examples are known from species OCCtlrS in sympalry with cenchoa al a Honduras (Wilson and Myers, 1982) and ad­ number of localities in Costa Rica and probably jacenl northem Nicaragua. On thePacil lC sIope is sympatric with inomatus al some siles on the of northem Central America the specios is ... Atlanlic lowlands. tricled lo eastoroChiapas, Mexico,and .dj ..... ' "'-'"'"--\c-:-+---l-----,i"

'";1-----1'0

9 r-----t-----t-----t-----r---� 9

K1LOtoIETEA$

• 1MANT000SSTRATUS GEMMl - 1500 lA CONTOUl 86·�------�------�8�5,------�------�84.------�------.��----�8

Fig. 4. Distribution of Irruzntooel gemmistratus in Costa Rica.

Guatemala, in !he premontane zone (600·1500 A second population seems to be represento m). The specíesis found in upland areas of Coso ed by Ihe Atlantie slope speeimens. They differ ta Rica and westem Panama on both versants from the Paeific samples in having low seg' and in the soulhwestem humid forests of Pa· mental counts, usually a series of definite la­ eifie lowland Costa Rica and adjacent Panama, teral spots broken off from the dorsal dark and thence southward in evergreen lowland foro blolehes on the posterior portion of the body ests of Soutb America. and usually a lighter interspace color. Material from the central and northwest uplands (Tab. In Costa Rica (Fig. 4) two populations are 2) agrees closely with Atlantie slope speeimens, recognizible on Ihe basis of segmental counts allhough the northwest upland snakes have the and coloration (Tab. 2). The population from dorsal interspace areas rather dark. For Ihis rea· Ihe Paeifie versant has high subcaudal and ven· son these upland examples are considered to tral plus subcaudal counts, rarely has any late· represent the Atlantie population. These ral blotehes broken off from Ihe dorsal body speeimens also agree very elosely with Myers blotehes and has Ihe interspaces between blot· (1982) series of cenchoa from the Atlantie ches very heavily darkened. In aIl these features slope of western Panama and seem to represent it agrees with cenchoa froID westem Panama the same population as well. and logelher they seem to be disjunct from A single example of 1. cenchoa from the eity Atlantie slope populations. of San José (NHMW 25472.1) is intennediate in $A VA GE & SC01T: Imantod" of Costa Rica 123

locale and characteristics between Atlantic and Atlantic 10wland series closely resemb1es Mese­ Pacific populations. It is a femalo with 250 la Central samples. The relalively hlgh segmen­ ventrals (similar to Pacific examples), 421 total lal counls for Ihese samples, which overlap the aegments (most like the Pacific population), lower range of varialion for Atlantie and upland 48 body blolches (most like AUantic specimens cenchoa contribuled subslanlially lO our earlier and 14 poslerior body blotches with laleral and erroneous appraisal Ihal Ihe latter and spots (mosl like Atlantlc examples). Very lileely "species A" were conspecific (Savage, 1973, Ihere was, prior to the very rapid and recent 1976, 1980; ScoII, 1969, 1983). Now Ihal we uplift of Ihe cordillera separating Ihe Atlantic have shown Ibal Ihis is nol Ihe case,it remains section of the Meseta Central from the Pacific to establish Ihe name for "species A". part , or still is, a connecti,on between the two cenchoa populations in thls region. The point is mool in any evenl sinee Ihe dis­ THE STATUS OF lMANTODES tinctive features of Ihese Iwo populations are GEMM1STRA TUS encompassed within the variation of cenchoa throughout its range as described by Myers The name Himantodes gemmistratus was (1982). For Ihis reason, and those expressed proposed by Cope (1861) for a snake from El by Savage and Heyer (1969), we agree wilh Ihe Salvador: Provincia de Sonsonale: near Volcán laller authors thal Ihe recognition of these or de lzaleo, formerly al Ihe Academy of Nalural other populations nomenclalurally as s.ubspe­ Sciences in Philadelphia, but now apparently eies serves no use fuI purpose . los1 (Malnale , 1971; Myers, 1982). Cope's The rather low segmenlal counts for Ihe descriplion is limit�d bul Ibere is no question Atlantic and upland population as compared Ihal Ihe El Salvador example of Imantades is to those for cenchoa in Ihe Pacific lowlands of sorne form olher Ihan cenchoa, wilh relalively Costa Rica and over much of its range contri· narrow verlebral seales and 42 body blolches buted to our mistaken belief Ihal cenchoa and (Smilb , 1942). l. cenchoa is nol known to "species A" a position that we now vehemently oecur in El Salvador. The few speeimens of Ihe eschew . (The northweslem and Mesela popu­ genus known from El Salvador (Mertens, 1952; lations had higher counls than pulative gemmis­ Yingling, 1972) have a range of 219-233 ven­ tratus and overlap with the Atlantic series of trals, 124-136 subcaudals, 346-357 lolal seg­ Ihe former) integraded (Savage 1973; 1976; menlal counls and 41-47 body blotches and we 1980; Scot 1969; 1983. presume Ihat Ihe hololype of gemmistratus was The third Costa Rican form , "species A", is conspecific wilh Ihem. clearly allied to those snakes referred to Iman­ Smith (1942) proposed Ihal Ihe name · todes gemmistratus by Myers (1982) in Panama gemmistratus be applied lo Ihe species of and from elsewhere in Middle America by Imantodes having Ihe enlarged verlebrals only olbers (Smilh 1942; Zweifel 1959; Peters and aboul Iwice as wide as Ihe lalerals, Ibal oc­ Orejas-Miranda, 1970). As already poinled out curred from Chiapas, Mexico soulh Ihrough above , "species AH may be consistently dis· Pacifie slope Cenlral America lo Panama, and linguished from Ihe Panama sample in having Ihal ha� usually been called elegans (Himantodes higher subcaudal and ventral plus sub caudal cenchoa varo elegans Jan and Sordelli, 1871) by counts. In addition, as shown below, "species previous aulhors. Smilh hado seen no examples A" is similarly distine! from several olher no­ from El Salvador or Honduras, and accepled minal populalions of gemmistratus from else­ E.R. Dunn's apparenl conclusion Ibat specimens where in Cenlral America. from Chiapas, Mexico, Gualemala a{Id Ihe Iype In Cosla Rica this form predominales in Ihe of gemmistratus were conspecific wilh Nicara­ drier formalions of Ihe Pacific lowlands and on gua, Cosla Rica and Panarna examples. The Ibe Mesela Cenlral, bul is also found al scat­ hololype of elegans was known from a non­ t lered localilies wilhin Ihe lowland evergréen specified localily in 'Ceniral America". foresls on Ihe Atlantic slope and in Ihe PaciÍic Smilb (1942) recognized a number of soulhwesl zone (Fig. 4) There is a general olher species of Imantodes in whlch Ihe verte­ smoolh clinal increase soulh lo norlh along Ihe bral scale row was sli¡hlly or nol al aJl enlarged, Pacific versanl in segmenlal COW1tS with Ihe Me­ as occurring in Mexico and northeaslem Cenlral teta Central examples usually inlermediale. The America. Subsequenl workers (Pelers, 1954; 124 REVISTA DE BIOLOGIA TROPICAL

Zweifel, 1959; Yingling, 1972) have placed all El Costa Rica Panamá of tliese fonns, wilh the exception of the very Salvador� distinctive Yucatan snaJee, lmantodes tenuissi­ Sub

Subcaudals 124 - 136 135 - 154 Ventrals 232 212 241 - 261 Subcaudals Ventrals plus 136+ 136 146 - 155 Ventrals Subdaudals 346 - 357 376 - 404 plus Body Blotches 41 - 47 51 - 73 Subcaudals 368+ 348 396 -408 Body Blotches 47 41 48 - 61

These differences disappear, however, The Nicaragua examples from Departamento when the El Salvador gemmistratus are compar­ Rivas: Javilla , near lhe Costa Rica border ed to the total sample of "species AH and Pa­ (UMMZ 123041) and Departamento Granada: nama gemmistratus. In the following sumary Santa Cecilia (KU 101930), are very similar only the features for the two El Salvador snaJees to Northwest Costa Rica "species AH. of undetennined sex are included in lhat cat­ The single westem Honduras snaJee (LSUMZ egory (unde!.); R equals the total range of va­ 33739), from Departamento del Valle : 3.2 km riation for each sample; the single, unblotched NE Hcaro Galán, is more similar to El Salvador specimen (CRE 8261) of species A was not in­ examples lhan to Nicaragua - northwest Costa c1uded in calculating the mean number of body Rica series, but is well wilhin the Iimits of var­ blotches. iatioo fOI "species AU in Costa Rica. The upland Honduras snaJee (AMNH 70260) from Departamento Cortés: Agua Azul, agroes most El Costa Rica Panama closely with lhe El Salvador sample, a1though Salvador having a very low ventral coun!. The latter two specimens and lhe El Salvador series are most Ventrals distinctive from Nicaragua - Costa Rica and Pa­ d 231 - 249 227 - 237 nama samples inlhe consistently low number of 9 219 - 231 225 - 252 221 - 228 body blotches (41 - 47 in the norlh ; 41 - 53.3 Unc1et. 220 - 233 - 73 in Nicaragua - Costa Rica and 55 - 75 in Panarna). In lhis regard it should be pointed out R 219 - 233 225 - 252 221 - 237 lhat only one example of Costa Rican "species SAVÁ GE '* SC07T: 1"""" 00" ofCosta Rica 125

TABLE 3

G�lIPhlc Wlriation in lmantodes prnmiltratuHike .,mpk, from Maleo .1Id G.. ,.",.¡"

Venir'" plus BOOy N Venir'" Subcaudals Subcaudals Blotches Distribution

OUveri o 3 230-235 134-14<1 369-374 11th. Tehuantepec, 9 13 221-237 117-135 354-356 Otiapas, Mellico; R 38 216-237 11H4

IsthmuI of Tehuantepee of Oaxaca and Chia­ Guatemala through Panaroa, to the Magdalena pas, Mexico. eastwards into westem Guatema· VaDey of northem Colombia. Future colleet­ la is probleroatical. Peters (i954) believed lhat ing in areas north of Costa Rica is needed to aD Mexieo populations aDied to gemmistratus establish whether the apparant gaps in distri­ were linked through aliveri, a view accepted by bution are real or collecting artifacts. An es­ and expanded on by Zweifel (I959) and Yingl­ sentiaDy aDopatrie population of lhe speeies ing (1972). The aliveri population is separated oeeurs in the Atlantie lowlands of Costa Rica_ by a 480 km gap from between lhe Tehuante­ In Panama the speeies is confmed to the Pae­ pee region and the southem records of the west ifie sJope exoept in the oentral lowlands where a Mexico subspecies latistrilltus (Cope, 1887) contiguous series of records link Atlantie and and gracillimus (Günlher, 1895) in Guerrero. Paeifie locations (Myers, 1982, map 1). The range of aliveri is eompletely aDopatrie to that of the Atlantie versant population caI­ led Imantades splendidus luciadarus Oliver by KEY TO TIlE SPECIES OF ¡MANTODES IN COSTA RICA Smilh (I942). Thls forro ranges a10ng the lowlands from Veracruz into northem Guate­ The foUowing diagnostic key will seIYe lo diJtin.. mala and is aDopatrie to the northem Yucatán guish among tbe three species of blunt-beaded vine Península forro for whieh the name Dipsas snakes known lo occur in Costa Rica.. splendida was eoined by Günther (1895). la. Dorsal pattem usuaDy oC Iar¡e dark While variation in segmental counts and blotcbe� rarely unifonn ; vc:ntrals more body bloteh numbers among these aDopatrie !han 223; maxillary _lb 10-14+2 ' series overlap, marked differenoes in color pat­ d«pIy grooved fang s. . . . _ • . . _ . . 2 tem between the Atlantie versant and Pae­ ifie sJope samples may refleet significant dif­ lb. Dorsal pattern of sm.n clark spo" IDd speckles, sometimes lined up lo fonn fe rentiation. Our review of the literature and very narrow (no mOte. than 1 scale row material from scattered loca1ities in Mexico, long) crossbars;. 19&-218 ventrals; UO- does not aDow us to reaeh a defmite cortcJusion 132 subcaudals; maxillary teeth'17-21+2 as to whether aD represent a single speeies or fangs with shaDowgroo ves. . lnumtoder if ane or more are conspecific with Imantodes ino17llltul gemmistratus. As an aid to those who may 2a. Scales in vertebral row greatly enluged. wish to attaek thls problem we have provided a 3-5 times widlb of latetals; 31-62 (usual­ summary of segmental and body bloteh counts Iy 48 or less) broad dad:: dorsal body for eaeh aDopatrie sample (Tab .3). These data blotches (Fig. lA); 228-278 ventrals; 145-183 subcaudals. lwuzntode$ cenchott are from Smith (! 942), Zweifel (1959) and

Yingling (!972). Sinoe the latter did noto in­ 2b. Scales in vertebral row 1.2-2.5 tUnes as dieate lhe sex for his counts, R in lhe table wide as laterals¡ 41-73 (usually 49 or refers to the range of vari.tion for the feature more) dark dors¡a} bands or blotches lB, lC); 225-252 ventral.; 12� regardless of sexo (F"13 � , S4 subcaudals. l1rumtodes xemmistnlhll A final problem relates to the aDoeation of (he distinetive Panama population re¡arded as I. gemmistratus by Myers (1982). As shown In praetioe, espeeiaDy in the field, lhe dif­ earlier aImost aD Costa Rica - Nicaragua exam­ ferenoes in color pattem will irnmediately pies of lhe speeies may be separated from aD separate representatives of the tbree forros. Panama speeimens on lhe basis of subcaudals l. lmantodes inornatus is a yellowish snake wilh oounts and the associated ventral plus sub­ many smaD dark punetatians, but never wilh caudal oounts (Tali. 2). Nevertheless, sinoe de­ elearly defmed .. dark dorsal or tail band or blot­ fi nitive gemmistratus from El Salvador have ches. 1_ Imantades cenchoa has large dark similar segmental eounts to those found in Pa­ saddles (Fig. lA) whose oenters are ehestnut nama, we believe that no useful purpose will be brown to aImost red (bolh in Jife and after served by reoognizing lhe Panama population as preservatio!l). The dark markings in l. gemmis­ • distintt species. Imantades �emm;'trrltus trrltus ttnd to be less pronounoed than in ...ms to be comprised 01 a series of 5 or more cenchoa and are much narrower in longitudinal aDopatrie populatians ranging along lhe Pae­ extent and often have white oenters (Figs. lB, ifie versant of Central America from taslem lC). The around color of lhe latter speeies is SA VA GE d: SCOTT: /11UI1Itodes of Costa Rica 127

light brown to beige, wilh a dislinct yeDowish blotches. The lolal blolch positions in this hue in mosl examples from Ibe Pacific versant example are 56, a high number bul one found and many from the Atlantic as weD.lmIlntodes in olher examples of cenchoa, when fragmenls cenchoa most frequently has a dark to medium of Ibe poslerior blolches are counted as two brown ground color allhough sorne Atlantic blotches. The number of dark tail blotches lowland examples are light brown lO beige. (50), and the tail lenglb as a percentage of total The single unusuaI, essentiaDy unicolor, yel­ length (28.1), as noted by Myers (op. cit.) for lowish hued gemmistratus (CRE 8261) from tbis example are typiCáI of cenchoa_ In cenchoa near Parrita is an exception to OUl initial sta te­ and gemmistratus the number of dark tail blot­ ment since it might be mistalcen for inomatus. ches is 22-53 and 28-42, respectively, and the In Ibe lalter narrow dark spots Ibal may be relative tail length 26-34'11>and 24-28'11> ,respect­ lined up lo form lines are always present, while ively. While Mye¡s (op. cit.) states that Ibe Ibe Parrita rarity is unspotted. width of the vertebral scale rows (2.5 x laterals) In juvenile l. cenchoa the centers of the dor­ in this example resemble gemmistratus our sal blotches usuaDy are nearly red and conlrast exarnination indicates that the rows near mid­ to Ibe black blotch outline. In one example body approach 3 x laterals, wruch is near the (CRE 4607) the blolchs are solid black. Onlo­ lower limits of variation for cenchoa. We ,eneticaDy Ibe blolch colors seem lo change lO suspect tbis difference may be an artifact of !he typical chestnut brown fround in most measuring technique , since. Myers compared adults. Juvenile l. gemmistratus on Ihe otber Ibe width of Ibe vertebral scaIes to Ibe mid­ hand, have dark brown blotches or bands, Ibat lateral scales. Most other workers and we appear to lighten in oolor during ontogeny-. oompared Ibem to the upper lateral seale: The white blotch centers fo und in sorne nearer the vertebral series. In any event Myer: examples (Fig. I C) are not present in any ju­ (p. 15) mentions 2.5 x laterals as the lowe veniles. The,., differences malee it relatively limil of variation in vertebral scale width in Pa­ easy to determine Ibe identity of juvenile nama cenchoa. specimens (verified by examination of Ibe in light of the above we regard KU 80260 vertebral scaIe row) without needing to under­ :;I.S a juvenile 1. cenchoQ with characteristic scala­ talce Ihe arduous task of making segmenta! tion, proportions and color , but with an unusual counts in most cases. amount of fragrnentation of its dorsal body We have examined an unusual juvenile blotches, posteriorIy . example (KU 80260) of ImIlntodes from Pana­ má Ibought lo be an aberrant gemmistratus by Myers (1982: 15). This little snalce has 255 DISTRlBUTlONAL PATTERNS ventrals, 155 subcaudals, 410 tolal segmental

oounts and 64 body blotches. In these fealures Geograpbic occurrence: - The following list except Ihe high number of blolches, the exam­ contains Costa Rican records of unquestionable pie resembles Panama cenchoa (Tab. 1). The identity based upon exarnination of specirnens blotch coloration (black-outlined, reddish blot­ or the literature and forms Ibe basis for the ches) and silape on the anterior part of the distributional maps (Figs. 3-5). body conforms to the discription of Costa Rj­ ImIlntodes cenchoa: ALAJUELA: Montes ca juveniles as given aboye and for Panama del Aguacate; Aguas Claras de Grecia ; Barranca juveniles described by Myers (op. cit.). The de Río Sarapiquí, Isla Bonita; Esperanza; 5 unique pattem of tbis example consists of a km W La Fortuna; 8 km W and Quesada; El series of about 31 typical blotches on Ihe an­ Venado de Grecia ; CARTAGO: Azahar; Río terior portion of the body. They are foDowed Chitaria ; Irazú; Moravia de Chirrip6 ; Navarro ; by about 15 blotches in wbich many are Finca Silvestre ; Tres Equis. Turrialba; HERE­ asymmetric (i.e. off-set on one or the other DlA: La Selva; GUANACASTE: San Bosco ; side) or are represenled onIy on one side. A few 2.2 km E Los Angeles; El Silencio; Tenorio ; of the latter barely eross over the midline onto 2 km NW Tilarán; LlMON: Bambú ; Fila Caro the opposite side and would be included in a bón; Cobal; Los Diamantes; 23 km NE Guápi­ oount such as Myers' (64 blolches "as counted les; Hamburgo ; Río Jiménez ; Pto. Limón; La from left side"). The fm al 16 blotches are lIDaD Lola; 24 Mili•• de Santa María; Pandora; Re­ spots that represent fragmenlation of 8 ventazón; Sipurio; Siquirres; btwn. Suraya and " 1---'''' ",----1----+----4 "

l0t--"'\ '"""'11------1'0

9 r---�-----r----t_----r_�� o

KILO"ETtRS

• IMANTOOES INORNATUS - 1500 M CONTOUR

�L----�---�----L----ie4�---L----t.�--�e

Fig. 5. Distribution of lmontodes inonuztus in Costa Rica.

Río Yuani; Suretka; Tortuguero ; Pta. Vargas; NW Tilamn; LlMON: Santa Clara; Los Diaman­ Waldeck; Zent; PUNTARENAS: Boruca; Isla tes; Pandora; Pocora; PUNT ARENAS: Barran­ de Caño; Río Claro at Golfito tumoff; Golfi­ ca; Corralitos; Coto Brus, Campo 2.5; 2 km E to; 0.5 E, 1.5 km SW and Monteverde; 4.8, Jacó; Finca La Ligia, La Julieta; Quebrada Leo­ 14.1 km NW Ciudad Neilly; S km SE Palmar na; Puntarenas; San Miguel de Barranca. SAN Sur; 3,6, 8 km SW, 3 km SSW, 2, 3 km W, 3 km JOSE: Escazú; El Rodeo; Moravia; Pozo Azul; WSW Rincón de Osa; SAN lOSE: 0.5 km S and Quebrada Rodriguez, Santa Ana; San José; La Hondura; Río La Hondura; Moravia ; La Pal­ Barrios Las Americas and Dos Pinos, San José; ma; lAkm S Alto La Palma; San José. Santa Ana. Imantodes gemmistratus: ALAJUELA: lmantodes ¡nomatus: ALAJUELA; Isla Bo­ Aeropuerto Internacional Juan Santamaría; nita; Los Chiles; CARTAGO: Tres Equis; HE­ Monte del Aguacate ; Atenas; La Fosforera; REDlA: Cariblanco; La Selva; LlMON: Guápi­ Hda. Ojo de Agua; San Carlos; Hda. San Fer­ les; El Tigre ;PUNTARENAS: Las Cruces;Mon­ nando; SanJosecito; btwn. San Miguel and San­ teverde; Río Nuevo at Interamerican Highway; to Domingo; San Rafael de San Rainón; CAR­ Rincón de Osa and 3 km SW; SAN JOSE: San TAGO: Cartago; Río Chitaria; Río Macho; Tres Isidro de El General. Ríos; Turrialba; HEREDlA: Barreal, Vara Blan­ ca; GUANACASTE: Los Angeles; Cañas; Río This seems an appropriate place to elear up Corobicí, 7 km N"-' Callas; 1.6, 13, 20 km N, !he erroneous perpetuation by Myers (1982) 48-80 km S Liberia ; La Norma; La Pacífica; of two transliterations of locality data asociat­ Río Sandillal, 3 km NW Cañas; Taboga; 3 km ed originally by Cope (18940) with sorne syn- types of Ihe nominal form Himantades semi where it is found from near sea·level to 1500· fa scilltus. m along the Atlantic versant. In the southwest Pacinc portion of the country it is known oruy One of these errors relates to a syntype ot from lowland sites (2·55Om), but occurs oruy H. semifa cilltus (AMNH 17358) attributed to in more upland areas (395·150Om) in Pacinc "Sapurio". Talamancs. This specirnen was notthwestern Costa Rica. lis absence from the doubtless collected by the famed ornithologist lowlands of northwestern Pacifie cramage aceas José M. Zeledón, who was a founder of the in best explained by the.seasonal wet-dry climate Museo Nacional de Costa Rica, or one of rus and the resultant absence of evergreen forest in associates when in the Baja Talamanca area of Ihe region. On the Meseta Central where the soulheastern Costa Rica with William More clirnatesupports a forest somewhat intermediate Gabb in 1873·1874 (see Savage, 1970) or at a between the evergreen and deciduous forma­ later date. No place called Sapurio exists in Coso tions l. cenchaa is found between 100-1500m. ta Rica, but the Talamanca region administra­ Imantodes gemmlstratus, 00 the other hand, tive capital of the late 1800's was the village of is a common soake in the deciduous and Sipurio. transitional forests of Paeific Costa Riea and Another syntypic example of H. semifa s­ the Meseta Central, respeetively. In Ihe former cilltus (AMNH 17314) was part of a series of area it is found from near sea-Ievel to 500 m in Costa Rican forms sent to Cope by George K. elevation. The Meseta Central populalions are Cherrie in 1894. Cherrie was employed as a continuous with the lowland ones and range zoologist and taxiderrnist by the Museo Na· onto the surrounding sJopes up to 1936 m at cional from 1890·1895 (Carriker,1910; Gómez Ihe Paso Desengaño (Vara Blanca), but alI and Savage, 1983). Cope's 1893 and 1894 other records for the species are from lower papers mention the receipt of other examples elevations. from Cherrie. The species is aJso found at scat:tered ever­ green forest loealities in the Atlantic lowlands Cherrie worked under the direction of José and at two sites in the south-west Pacific M. Zeledón and visited many of the latter's area. 00 the Atlantic, gemmistratus generally favorite collectint sites. One of these is Pozo oceurs below 1000 m in elevation, but exam· Azul de Pirrís (Carriker, 1910; Zavage, 1974). pIes typical of the species oeeur in the gorge of The handwritten labels of reptiles from this site the Río Reventazón in the vicinity of Cartago sent to Cope by Cherrie seem to have been (J 400-1500) and are related through snakes transliterated by Cope to "Paso Azul" (1893), from intermediate localities (Turrialba 646 1894a) and "Pazo Azul" (l984b), but the fact m and Río Chitaria 660 m) to Atlantie low· Ihat the type of Leaptaphis u/tramarinus from land populations. the latter site was collected by Zeledón leaves little doubt as to the locality in question. lmantodes inornatus is an exclusively Atlantic Savage (op. cil.) inadvertantly created another evergreen forest form nearly restricted to the error regarding this place which is in the Can· Atlanlie and southwest Pacinc lowlands in tón de Acosta, Provincia de San José (not Can Costa Rica. Three records indicate a penetra­ ton Aguirre,Provincia de Puntarenas). tion loeally into the premontane zone in the Cordillera de Tilarán (Monteverde, 1450 m) As an aside, it is interesting to note that Ihe north sJope of the Cordillera Central (Ca· Cherrie subsequently had a long career as an riblanco, 830 m) and in extreme southwestern explorer and zoologist, most particularly in Costa Rica (Las Cruces. 1200 m). association with the American Museum of Na­ tural History. Chere¡e, of course, was the Sympatric Occurrences. AS may be expected principal naturalist on the museum's Roosevelt· from the previous discussion of distribution, Rondon Expedition to Brazil (Roosevelt,1914; Imantodes cenchoa co·occurs with the other Cherrie, 1930) and worked for the museum's species of the genus at sorne localities in Costa ornithology department for a number of years. Rica. There are no known instances of l. gem­ Ecologic Occurrence. Imantades cenchaa mistratus and 1. inarnatus being found at the has a broad range throughout the lowland and same site. Documented sympatry or virtual premontane everjlreen forest of Costa Rica, sympatry is provided by the listing below: L c:endloa LocaIity 1. gernmistratus

CRE 3261 Guanacaste : 2.2 km E Los Angeles de Tilarán Los Angeles de Tilarán UMMZ 131406 AMNH 17274 A1ajuela : Montes del Aguacate AMNH 17316/ 17330·31 NHMW 25472.1 San José: San José nume¡ous examples: ZMH ROl980 AMNH,MCZ, NHMW, UMMZ,UCR KU 34032 Cartago: Turrialba KU 35508.()9 KU 35635·36 UCR 214243 Cartago: Río Chitaria UCR 6276 KU 25680 Limón : Los Diamantes KU 13496 KU 25700 FMNH 101245 UMMZ 131409 Alajuela : San Carlos UMMZ 131409Z FMNH 103121 A1ajuela ; Isla Bonita KU 25158 numerOllS Heredia; La Selva numerous examples; CRE, examples CRE, UCR UCR CRE 2931 Cartago; Tres Equis UCR 3413 CRE 851, 4461, Puntarenas: Monteverde CRE 7201 4588, 4607, 8056 nurnerous examples: Puntarenas: Rincón de Osa LACM 11414243 CRE

ACKNOWLEDGEMENTS who loaned material and provided scale counts for critical specimens in their care ; and R.w. Many individuals �d institutions have McDiarmid, now of the United States Fish and cootributed to the preparation of this paper Wildlife Service, for his aid in the field and during the period of over twenty years that we laboratory . have been working in Costa Rica. We partic­ We a1so thank Oana M. Krempels and Steven u1arly wish to thank the following for providing O. Werman, of the University of Miami, for material in their care for data analysis (abbrevia­ preparing the fi gure of snake pattems and the tions in parentheses are used throughout this photographs and maps, respectively. report in citing particular specirnens): E.N. Throughout our work in Costa Rica, we have Amold, British Museum of Natural History been aided by the staff and facilities of the (BMNH); W. Auffenberg, Florida State Museum Organization for Tropical Studies (OTS). The (FSM); W.E. Ouellman, University of Kansas study was initiated while the senior author was (KU); W.R. Heyer (USNM); R.F. Inger, H. a John Sirneon Guggenheirn Memorial Fellow. Marx , & H.K. Voris, Field Museum of Natural We acknowledge with many thanks the support History (FMNH); H·W. Koepcke, Zoologisches of the latter two sources. Museum, Hamburg (ZMH); A.G. Kluge, Univers­ ity of Michigan , Museum of Zoology (UMMZ); Oougias A. Rossman, Larry David Wilson, RESUMEN Museum of Zoology , Louisiana State University (LSUMZ); and F. Tiedmann, Naturhistorisches lmantodes inornatus e lmantodes cenchoa se Museum. Wien. encuentran en Costa Rica y recientemente se We especially acknowledge the special aid ha adelantado una hipótesis en el sentido que provided by S.B. Emerson of the Field Museum. l. cenchoa es una amalgama de dos especies: He worked with the junior author in analyzing I. cenchoa e l. gemmistratus. El análisis de los the original data set; C.W. Myers, American datos de escamación y coloración de los ejem­ Museum of Natural History (AMNH) and O.C. plares de Costa Rica confirma que este comple­ Robinson, University of Costa Rica (UCR), jo está compuesto por dos especies, una de las cuales es obviamente l. celle/lOa, de amplia dis­ Cherrie, G.K. 1930. Dark Trails. G.P. Pulnam's, New tribución. que en Costa Rica se encuentra en York, New York. las tierras bajas del Pacífico sudoccidental, en la Cope, E.D. 1861. Catalogue of the Colubridae in the Meseta Central, en las bajuras del Atlántico y en Museum of the Academy of Natural Sciences of las estribaciones de las cordilleras y en la ver­ Philadelphia, with notes arid descriptions of new tiente de los montes del Pacifico norte. No se le species. Part 2. Proc. Acad. Nat. Sci. Phila., 12: encuentra en las bajuras del Pacifico noracd­ 241-246. dental. Una segunda especie ocurre en las baju­ Cope, E.D. 1866. Contributions to the ophiology of lower California, Mexico and Central America, ras del Pacífico noroccidental y en simpa tría Proc. Acad. Nat. ScL Phila. 13:292-306 .. con cenclzoa en la Meseta Central y en varias localidades de las bajuras del Atlántico y del Cope, E.D. 1867. Fifth contribution 10 the herpctolo­ Pacífico Sudoccidental. La segunda forma es gy of tropical America. Proc. Acad. Nat. Sci. Phila. 18: 317·323. alopátrica con gemmistratus de Panamá y difie­ re consistentemente de esta última con respec­ Cope, E.D. 1887. Catalogue of batrachians and reptiles to a la escamaci6n. Una revisión de los demás of Central America and Mexico. Sull U.S. Natl. ejemplares centroamericanos y mexicanos asig­ Mus., 32: 1-98. nados a /. gemmistralus (localidad tipo: El Sal· Cope, E.D. 1893. Second addition to the knowledge vador: Sonsonate: cerca del Volcán Izalco) in­ of the Batrachia and Reptilia of Costa Rica. Proc. dica que los ejemplares costarricenses son coes­ Amer. Philos. Soc., 31: 333-345. pecíficos con ellas. La especie aparentemente está compuesta por tres sub poblaciones alopá­ Cope, E.D. 1894a. On the species of Himantod.es D. & B. Amer. Nat., 28: 612-614. tricas a lo largo de la vertiente 'del Pacífico: El Salvador-Honduras; Nicaragua..costa Rica; y Pa­ Cope, E.D. 1894b. Third addition to a knowledge of namá. Existe, además, una cuarta subpoblación, the Batrachia and Reptilia of Costa Rica. Proc. más o menos alopátrica, en la vertiente atlánti­ Acad. Nat. ScL Phila., 46: 194-206.

ca de Costa Rica. Cope, E.D. 1899. Contributions to the herpetology of Es problemático el estatus sistemático de las New Granada and Argentina with dcscriptions of poblaciones alopátricas del este de México y de new forms. Ph ila. Mus. Sci Bull. , 1: 1-22. la Península de Yucatán, asignadas recientemen­ Gómez, L.D. and J.M. Savage. 1983. Searchcrs on Ihat te por varios autores a gemmistratus. Otras po­ rich coast; Costa Rican ficld biology, 1400-1980. blaciones del Istmo de Tehuantepec y del oeste pp 1-1 1. In D.H. Janzen (ed.) Costa Rican Natural de México parecen candidatos más probables de History. Univ. Chicago Press. ser coespecíficos con gemmistratus, aunque es­ Günther, A.c.L.G. 1885-1902. Reptilia and Batrachia. to no se puede resolver con los datos que exis­ Biol. Centt. Amer. London. ten en la actualidad. Debe hacerse mención a una variación singular de un solo color de la ver­ Jan, Giorgio and Ferando SordeUi 1860-1 881. Icono­ tiente del Pacífico de Costa Rica. Imantodes graphie generale des Ophidiens. Milan. inornatus y cenclzoa están restringidas (limita­ Malnate, E.V. 1971. A catalog of primary types in the das) a los hábitats del bosque perennifolio. herpetological collections of the Academy of Na­ mientras que gemmistratus es r:1ás abundante en tural Sciences, Philadelphia (ANSP). Proc. Acad. los bosques caducifolios a lo largo de las costas Nat. Sci Phila. 123: 345-375.

occidentales de Centro América y México. Esta Mertens, R. 1952. Die Amphibien und Reptilien von última especie se encuentra ocasionalmente en El Salvador, auf Grund det Reisen von R. Mettens los bosques perennifo lios en la vertiente atlán­ und A. Zilch. Abhandl. Senckenbetg. Natur. Ges., tica de Costa Rica y en el centro de Panamá. 487: 1-120. I Se sabe que cenclwa y gemmistratus son sim­ Myers, C.W. 1982. Blunt-headed vine snakes (Imanto­ pátricas en varios lugares de Costa Rica pero no des) in Panama, including a new species and other así l. inornatus y la segunda especie. A menudo revisionary notes. Amer. Mus. Nat. Hist. Novitates, se captura a l. cenchoa y a inornarus juntas. 2738: 1-50.

Oliver, J.A. 1942. A new snake of the genus Im anto­ L1TERATURE CITED des from Mexico. Copeia, 1942: 1-2.

Ouriker, Jr., M.A. 1910. An annotated list of the birds Peters, lA. 1954. TIte amphibians and reptiles of the of Costa Rica inciuding Cocos Island. Ann. Carnegie coast and coastal Sierra of Michoacán, Mexico. Mus., 60314·970.• Oce. Paps. Mus. ZooL Univ. Michigan, 554: 1-37. 132 REVISTA DE BIOLOGIA TROPICAL

Piten l.A. and B. Orejas-Miranda. 1970. Catalogue of Scott, N.J. 1969. A zoogeographic anaJysis of the the Neotropica1 Squamata. Part. 1. Snakes. Bull. snakes of Costa Rica. Ph. O. Dissertation, Univ. V.S. Nat!. Mus., 297 : 347 p. Sou th. calif.

Roosevelt, T. 1914. Through the Brazilian wilderness. Scott, N.J., 19 83. Imantodes cellchoa (Bejuquilla, Scribncr's New York, New York. Chunk-hcaded snake), p. 402 In O.H. Janzcn (ed.). Costa Rican Natural History. Univ. Chica­ Savage, J,M. 1966. The origins and history oC the go Press. Central American herpetofauna. Copeia : 719-766. Smith, H.M. 1942. Mexican herpctological miscellany. Savage, 1.M. 1970. 00 the trail of the golden frog : Proe. U.S. Nat!. Mus., 99: 349-395. with Warszewicz and Gabb in Central America. Proc. Calif. Acad. Sci.. 273-288. TayJor, E.H. 1951. A brief review of the snakes of Costa Rica. Univ. Kansas ScL Bull., 34: 1-188. Savage, J.M. 1973. A preliminary handlist oC the Herpetofauna oC Costa Rica. Univ. Soulh. Calif. TayJor E.H. 1954. Furtherstudies on the serpents of Costa Rica. Univ. Kansas Sci-BuIl., 36: 673-801. Savage, J.M., 1974. Type localities foc species oC amphibians and reptiles described from Costa Ri­ Wilson, L.O. and J. R. Mcyer. 1982. The snakes of ca. Rev. Bial. Trop., 22(1): 71-122. Honduras. Publ. in Biol. and Ceo!. Milwaukee Pub. Mu •• 6: 1-159. Savage J.M., 1976. A preliminary handlist oC the herpe­ Yingüng, R.P. 1972. A review of the colubrid snake tofauna of Costa Rica. 2nd ed. Ed. Univ. Costa lmantodes gemmistratus. M.S. Thesis, San Diego Rica. State Univ.

Savage, J.J., 1980. A handlist with preliminary keys to Zweifel, R.G., 1959. Snakes of the genus Imantodes the herpetofauna of Costa Rica. Allan Hancock in western Mexico. Amer. Mus. Nat. Hist. Novitates, Found., Univ. South. Calif. 1961 : 1-18.