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AMERICAN MUSEUM Norntates PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET, NEW YORK, N.Y. 10024 Number 3027, 12 pp., 6 figures November26, 1991

The Lizard Genus Sphenomorphus (Scincidae) in Panama, with Description of a New Species

CHARLES W. MYERS1 AND MAUREEN A. DONNELLY2

ABSTRACT Greer assigned three species of Middle Ameri- langeal formulae, and male genitalia. Sphenomor- can skinks to the otherwise Indo-Australian phus cherriei is a widespread skink found at the Sphenomorphus, a plesiomorphic taxon. Sphen- southern limits ofits range on the Pacific lowlands omorphus rarus, new species, extends the New ofextreme western Panama. A smalljuvenile from World range ofthe genus southeastward to the end the Atlantic lowlands also is reported, although its of the Cordillera de Talamanca in western Pana- assignment to cherriei is provisional since it falls ma. The new species is based on a specimen from somewhat outside the range ofvariation ofnearly 780 m in lower montane rain forest. It is most 300 Costa Rican and western Panamanian spec- similar to S. cherriei (Cope) but is readily diag- imens examined. nosed by diverse characters of scutellation, pha-

RESUMEN

Greer asigno tres especies de escincidos me- 780 metros de altitud en la selva pluvial montana soamericanos a Sphenomorphus, un genero ple- baja. Esta especie es mias parecida a S. cherriei siomorfico por otra parte de la region indo-aus- (Cope) pero parecer a ser diagnostica facilmente traliana. Sphenomorphus rarus, especie nueva, por caracteres diversos de las escamas, f6rmulas extiende la distribucion del genero en el Nuevo de las falanges, y de los genitales masculinos. Mundo hacia el sudeste hasta el final de la Cor- Sphenomorphus cherriei, un escincido amplia- dillera de Talamanca en el occidente de Panama. mente distribuido en America Central, tiene su La especie nueva se basa en un especimen de los limite de distribucion en las tierras bajas del Pa-

1 Curator, Department of Herpetology and Ichthyology, American Museum of Natural History. 2 Boeschenstein Research Fellow, Department of Herpetology and Ichthyology, American Museum of Natural History.

Copyright © American Museum of Natural History 1991 ISSN 0003-0082 / Price $1.60 2 AMERICAN MUSEUM NOVITATES NO. 3027 cifico al oeste extremo de Panam'a. Una lagartija algo fuera del intervalo de variacion de casi 300 juvenil y muy pequeiia de las tierras bajas del Ca- especimenes examinados de Costa Rica y Panama ribe se presenta tambien aqui, aunque su asigna- occidental. cion a la especie cherriei es provisional porque cae

INTRODUCTION The Middle American herpetofauna in- southwestern headwaters of the Rio Guabo, cludes three seemingly related small skinks 780 m elev. (8°47'N, 8211 'W), Province of (assatus, cherriei, incertus) that until recently Bocas del Toro, western Panama. were referred to the genera Lygosoma (e.g., ETYMOLOGY: The species name is a Latin Stuart, 1940), Scincella (e.g., Smith and Tay- adjective alluding to the rarity of this new lor, 1950), or Leiolopisma (e.g., Taylor, 1956; lizard, known from a single specimen. Stuart, 1963; Peters and Donoso-Barros, DIAGNosIs: A short-limbed New World 1970). Sphenomorphus (sensu Greer, 1979) lacking Greer (1974: 32-34) removed these genera supranasals and prefrontals, with single large from consideration and boldly transferred as- frontoparietal, single loreal, median pair of satus, cherriei, and incertus into Sphenomor- nuchal scales not enlarged, median pair of phus-a genus otherwise occurring "from preanal scales enlarged, low number (;26) southern and eastern Asia through the Indo- of rows of smooth scales at midbody, with a Australian Archipelago to the Solomon Is- median window (palpebral disk) in lower eye- lands and Australia" (Greer, 1979: 323). Vil- lid, and with phalangeal formulae of 2-3-4- la et al. (1988) used this generic arrangement 4-3/2-3-4-5-3. The several New World spe- but did not cite Greer in their "Bibliographic cies of Scincella (sensu Greer, 1974: 32), Checklist"-an omission which apparently which occur in Mexico and the United States, caused them to add a fourth New World spe- are most easily separated from New World cies, "Sphenomorphus" gemmingeri (Cope), Sphenomorphus by the presence of paired an unintentional new combination for a Mex- frontoparietals. ican species that Greer (1974: 32) had placed Sphenomorphus rarus appears to be readily in Scincella. distinguished from all its New World con- In any case, zoogeographic conclusions geners (as well as from New World Scincella, must not yet be drawn from the New World see above) in lacking prefrontal plates, and distribution because Sphenomorphus is a ple- in having the frontonasal plate markedly con- siomorphic taxon not at present definable by cave posteriorly and in broad contact (owing derived characters. It is a taxonomically "re- to absence ofprefrontals) with the frontal (fig. sidual group" (Greer, 1979: 322) ofover 120 2). species; it serves as a convenient repository Sphenomorphus rarus is additionally dis- for the New World (and other) species pend- tinguishable from Costa Rican and Pana- ing further phylogenetic analysis. manian populations of its geographically The purposes of the present paper are to closest relative, S. cherriei, in having (1) few- describe a fourth species of Sphenomorphus er subdigital lamellae on the fourth toe (11 (fig. 1), from the southern end of the New in rarus vs. 13-18 in cherriei), (2) fewer mid- World range, and to document the occur- body scale rows (26 in rarus vs. 29-32 in rence of S. cherriei in Panama. cherriei), and (3) shorter limbs (digits of adpressed limbs widely separated by z 10 scales Sphenomorphus rarus, new species in adult d rarus, digits usually approaching to within a few scales or actually touching or Figures 1-3, 4A greatly overlapping in cherriei). The type HOLOTYPE: AMNH 129836 (field no. CWM specimen ofrarus further differs from the great 17250), an adult male caught by C. W. Myers majority of cherriei specimens in having a in company with J. W. Daly on January 13, single median window in the lower eyelid, 1983, in lower montane rain forest on the and in having one rather than two loreals. 1991 MYERS AND DONNELLY: SPHENOMORPHUS 3

Fig. 1. Sphenomorphus rarus, new species. The holotype (AMNH 129836) in life, approximately x 2.

There also are differences in phalangeal for- pair ofslightly enlarged dorsolateral nuchals, mulae and hemipenes -see Comparisons for separated by two small undifferentiated nu- further discussion and for practical differ- chals situated posterior to interparietal su- entiation from other Panamanian skinks or ture. Minute tubercles (presumed sensory or- skinklike lizards. gans) present on anterior head plates, being most numerous on rostral, frontonasal, and HOLOTYPE supralabials. DESCRInrION OF Nasal rhomboidal, longer than high, with The undissected holotype is a male, ap- naris centrally situated; nasals widely sepa- parently adult, with everted hemipenes. rated by frontonasal. Loreal one. Preoculars Length from tip of snout to vent (SVL) 52 two. Superciliaries eight; first superciliary mm; snout to eye 3.2 mm; snout to ear 9.0 largest, in contact above with posterolateral mm; snout to base of forearm 17 mm; trunk edge frontonasal and (narrowly) with antero- length from axilla to groin 27 mm; greatest lateral edge frontal, in contact below with up- head width (between angles ofjaws) 7.2 mm; per preocular and (narrowly) with loreal. Cil- greatest body width 9.0 mm. Tail partly re- iaries 10/8; a small scale interposed above generated, 49 mm in length (total length 101 + anterior ciliary and below suture between first mm). Limbs pentadactyl (5th toe ofleft fore- two superciliaries. Scales (lower ciliaries) limb missing due to injury) and short, well along edge of lower eyelid 15/12, the first separated by space of 10 scales when ad- lying posterior to suture between preoculars. pressed against body; straightened limbs Lower eyelid movable, scaly, with elongated measuring (from insertion to tip of longest median window (fig. 2). Subocular row in- digit) about 9 mm forelimb (17.3% SVL), 15 complete, separated by fourth supralabial be- mm hind limb (28.8% SVL). low center of eye, with three presuboculars Snout rounded in dorsal and lateral aspect. and two postsuboculars. Several small pre- Rostral twice as wide as high, in broad con- temporals. Primary temporal one, separated tact with frontonasal posteriorly. Frontonasal from parietal by a pretemporal. Secondary wider than long, with posterior margin temporals two, the lower larger than primary broadly and conspicuously concave. Prefron- temporal. Six supralabials on each side. tals absent. Frontal longer than wide. Fron- Six infralabials on each side; mental more toparietal single, the largest plate on head. than twice as wide as long; postmental longer Four large supraoculars on each side. Inter- than mental, in contact with first two infra- parietal relatively small, triangular; pineal eye labials on each side; three pairs of enlarged poorly defined, situated in posterior half of chin scales, with first pair in broad contact, interparietal. Parietals much wider than long, second pair separated by one scale row, third in contact behind interparietal, laterally in pair separated by three scale rows. contact with upper secondary temporal. A External ear opening a large vertically 4 AMERICAN MUSEUM NOVITATES NO. 3027

3 mm.

Fig. 2. Head of Sphenomorphus rarus, new species (AMNH 129836, holotype). Translucent (i.e., nonpigmented) scales of the lower eyelid are shaded gray. aligned oval (smaller than eye opening), with- Forefoot, I 3/4 II 5/6 III 7/7 IV 7/7 V ?/4. out lobules or spines. Scales smooth and un- Hind foot, I 3/3 II 8/7 III 9/11 IV 11/11 striated, in 26 rows around midbody; 29 rows V 6/5. around neck just anterior to forearm; about Median pair ofenlarged preanal scales (about 19 rows around base of tail. Paravertebral 1.5 x size of adjacent ventrals), each over- rows (from end parietals to midlevel between lapping part of a smaller outer preanal scale thighs) each with about 55 scales. Trunk scales on each side. Subcaudals on base oftail nearly nearly equal in size dorsally and ventrally. as large as ventrals; subcaudals widened on Scales of limbs smooth and unstriated as on regenerated part of tail. body. Supradigital scales paired except for COLOR PATTERN: In life (fig. 1) dark brown single distal scale; upper and lower ungual- above, turning yellowish on lower sides; a sheath scales short, covering only base ofclaw; black stripe from side of snout through eye subdigital lamellae rounded. Digits short, as and above ear, ending slightly posterior to reflected in lamellae counts, as follows (Ro- shoulder, edged below by a pale yellow post- man numerals = digits, Arabic numbers = ocular stripe from eye to ear. Underside of subdigital lamellae on left/right feet): head and throat gray save for a few flecks of 1991 MYERS AND DONNELLY: SPHENOMORPHUS 5

Fig. 3. Ventral view ofholotype of Sphenomorphus rarus, photographed before preservation, about x 2. The pale areas of pigmentation on throat and venter were golden yellow. golden yellow, which becomes the predom- the total length. The deeply entrenched sulcus inant color ofthe venter (fig. 3); underside of spermaticus forks a short distance below the tail gray, becoming blackish near the tip; un- lobes (about 44% ofdistance from base) and dersides oflimbs dull greenish yellow, palms the branches extend onto the lobes in a cen- and soles black. Iris dark brown. Notched trolineal orientation, terminating well below tongue black above. the apices of the lobes. The basal part of the In preservative a lighter brown. Scattered hemipenis is widened in sulcate or asulcate melanophores between the anterior dorso- view; a pronounced collarlike swelling below lateral black stripes become posteriorly co- the lobes forms a distinct overhang on the alesced, forming six poorly defined, dark, asulcate side (but does not give the organ a dorsal lines starting at level of forelimbs and "capitate" appearance). The distal part ofeach extending posteriorly along body and onto lobe bears two enlarged flaps of tissue, one tail (these lines barely evident in life). Su- rounded and one pointed, to the lateral side pralabials and infralabials irregularly blotched of each sulcus branch near its termination. and spotted with brown; side of neck and The lobes of the hemipenis are strengthened flanks pale, with dark brown spots and flecks by thick, elongated folds oftissue, which are (also evident in life, fig. 1). Limbs irregularly somewhat variably arranged so that the lobes spotted, almost reticulated, in light and dark are not mirror images. The organ is spineless brown, this pattern more evident in preser- and lacks visible microornamentation at x 50 vative than in life. Ventral surfaces immac- magnification. ulate white, except undersides offeet and re- OSTEOLOGY: Based on an X-ray photo- generated part of tail pale brown. graph, the phalangeal formula for the hand HEMIPENIS: The hemipenes were almost is 2-3-4-4-3 and for the foot 2-3-4-5-3. There fully everted at time ofpreservation. The left are 26 presacral vertebrae including the atlas. organ was removed from the specimen, soft- FIELD NOTE: The holotype was active dur- ened successively in glycerin and in a solution ing a sunny afternoon, in ground litter on a of trisodium phosphate, and reinflated with forested slope. carmine-dyed petroleum jelly. The inflated hemipenis (fig. 4A) of the holotype is 9 mm COMPARISONS long. It is a thin-walled, deeply bilobed struc- Sphenomorphus rarus needs be compared ture, with the lobes comprising 44 percent of only briefly with Sphenomorphus assatus 6 AMERICAN MUSEUM NOVITATES NO. 3027

one of these (cherriei) currently is so regard- ed.

COMPARISONS WITH SPHENOMORPHUS CHERRIEI As presently constituted, the third named species of New World Sphenomorphus-S. cherriei (Cope) -ranges from Veracruz, Mex- ico to Panama. It is a longer legged species than any ofthe others and has a higher number ofmidbody scale rows (30-36) according to Stuart's (1940: 5) treatment. The type locality of cherriei is in Costa Rica,3 the area that has provided the greatest number ofmu- seum specimens of this species. Costa Rican and Panamanian cherriei seem to resemble rarus somewhat more closely than do specimens from farther north. For these reasons, rarus is compared below mainly with specimens from southern populations of cherriei. COSTA RICA: Since Sphenomorphus rarus shows a superficial resemblance to southern S. cherriei, a search (unsuccessful) for additional specimens ofthe new species was made in the extensive holdings of cherriei in the Costa Rican Expeditions (CRE) collection at Fig. 4. Male genitalia ofSphenomorphus from the University ofMiami. Initially, 223 spec- lower Central America, shown in sulcate (left) and imens ofcherriei were examined from 40 lo- asulcate (right) view; x 9 (scale lines = 1 mm). A. calities in seven Costa Rican provinces, as Fully everted left hemipenis of S. rarus, AMNH follows (province and number of localities 129836, holotype (52 mm SVL), western Panama. followed by number of specimens in paren- B. Partially everted left hemipenis of S. cherriei, theses): Alajuela 3 (3), Cartago 4 (21), Guan- AMNH 104424 (55 mm SVL), Great Corn Island, acaste 6 (23), Heredia 4 (53), Limon 8 (51), Zelaya, Nicaragua. Puntarenas 12 (68), San Jose 3 (4). The above samples of S. cherriei provided information on variation in certain diagnos- (Cope) and S. incertus (Stuart) of southern Mexico and northern Central America. These two species somewhat resemble rarus in hav- 3Mocoa cherriei Cope (1893: 340-341), from Palmar ing a low number ofmidbody scale rows and [= Palmar Norte, Puntarenas Prov.], southwestern Costa relatively short limbs (usually nonoverlap- Rica. Based on a single specimen later deposited in the ping in adults), but they differ absolutely in American Museum (see Myers [1982: 23] for a brief the presence of prefrontals and two loreals, history of Cope types at AMNH). and in having 2 14 subdigital lamellae under The holotype (AMNH 9551), a juvenile 24 mm SVL, the fourth toe. Judging from the literature and is in poor condition but shows the following character- AMNH specimens of assatus, there may be istics that are consistent with our current concept of cherriei: Prefrontals present, with intervening posterior other in as well as in differences scutellation margin of frontonasal straight; two loreals; nuchals un- proportions and color pattern, but variation differentiated; 32 scales around midbody; 18/17 subdig- within these taxa is not well known (see Stu- ital lamellae under fourth toes; lower eyelid with window art, 1940, and Greer, 1974: 33). One or more of two panes (anterior smaller); adpressed limbs widely of the subspecies of S. assatus in Stuart's overlapping (4th toe extending past hand to reach upper (1940) account might warrant specific status; arm). 1991 MYERS AND DONNELLY: SPHENOMORPHUS 7 tic characters throughout the Costa Rican Lower eyelid single two or more window(s) range. All 223 cherriei specimens had two Midbody scale 26 29-32, x = 30.0, SD prefrontals (absent in the rarus holotype). The rows = 0.72 posterior margin of the frontonasal (mark- Paravertebral 55 60-67, x = 63.9, SD edly concave in rarus) was more or less scale rows = 1.91 straight in 142 specimens (64%) of cherriei, Rows betw. ad- 104 0-9, x = 2.6, SD = pressed limbs 2.88 convex in 78 (35%), and concave in but three 4th toe lamellae 11 13-18, x = 15.8, SD (1%) of 223 specimens; one of these (CRE = 0.93 849, Limon) is aberrant in having an azygous 4th finger lamel- 7 8-10, x = 9.6, SD = scale between the frontonasal, frontal, and lae 0.54 prefrontals. PACIFIC WESTERN PANAMA: A total of 13 Of the above sample, 193 specimens have specimens of S. cherriei are available from the lower eyelid closed enough to permit easy the Pacific lowlands of Chiriqui Province in coding for presence or absence of a single extreme western Panama (ANSP 21628, median window (present in rarus): Only two 21774-21776, Puerto Armuelles; ANSP (1%) cherriei have the median window (CRE 21779-21787, Burica Farm, Chiriqui Land 139E, Limon; CRE 281 lA, Cartago), where- Co.). One of these is an adult female (ANSP as 139 specimens (72%) have several small 21628, 53 mm SVL) and the other 12 are scales toward the center of the lower eyelid. juveniles (x SVL = 27.4 mm, SD = 4.01). An additional 19 (10%) of the cherriei spec- Variation in this sample: imens have a kind of window comprised of two equal or unequal "panes": 11 ofthese 19 Prefrontals present have two panes of unequal size (anterior Rear margin fron- straight (11) or undulating (1)5 smaller) and eight have panes equal in size. tonasal The remaining 33 (17%) of 193 specimens Anterior loreal present Lower eyelid win- two to several show bilateral asymmetry in the lower eye- dows lids, but none of these has a single median Midbody scale rows 30-32, x = 30.8, SD = 0.56 window. Paravertebral scale 63-67, x = 65.0, SD = 1.23 THE LA SELVA POPULATION: The general rows Rows betw. ad- 0-5 (0 in 11 juv., 2 in one juv., Costa Rican sample of S. cherriei included pressed limbs 5 in ad. 9) 47 specimens from the La Selva Biological 4th toe lamellae 15-18, F? = 16.7, SD = 0.96 Reserve (2.6 km SE Puerto Viejo de Sara- 4th finger lamellae 9-12, x = 10.0, SD = 0.77 piqui, Heredia Prov.) in northeastern Costa Rica. Subsequently, an additional 60 speci- AN ENIGMATIC SPECIMEN FROM ATLANTIC mens were examined from this locality (6 ju- WESTERN PANAMA: A single specimen of veniles, 2 females, 9 males, and 43 unsexed Sphenomorphus (AMNH 119063, fig. 5) is adults). These additional specimens were collected in 1972-1973 as part of a study of the 4 This separation would be "-5" scales if indirectly dynamics ofthe leaf-litter herpetofauna (Lie- calculated following Stuart's method (1940: 2-3), as fol- berman, 1986; Guyer, 1986; Donnelly, 1989). lows: axilla-groin length [27 mm] - (forelimb [9 mm] + Morphological variation summarized for this hind limb length [15 mm]) = 3 mm, a distance containing geographical and temporally well-defined 5 lateral midbody scales in the holotype of S. rarus (52 population sample reinforces the morpho- mm SVL). For 24 specimens of cherriei over 49 mm logical distinctions already made between SVL, Stuart (loc. cit.) gave a range offrom -1 scale (one Costa Rican cherriei and the Panamanian ho- specimen with limbs failing "to meet") to + 12 scales (x lotype of rarus, as follows: = +5 scales in "leg overlap"). On Stuart's plot for 75 cherriei and 39 assatus ofall sizes, the holotype of rarus would thus fall well outside the total range (-1 to + 24 Sphenomorphus La Selva for but near the midpoint of the range rarus S. cherriei scales) cherriei, (N=1) (N=60) (0 to -9, x = -4 scales) for equivalent-sized assatus. Prefrontals absent present 5 Another specimen (ANSP 21785) is aberrant in hav- Rear margin concave - straight or convex ing the frontonasal plate comprised of two asymmetric frontonasal scales (the left wider than the right), with the posterior Anterior loreal absent present border being concave at the junction of these scales. 8 AMERICAN MUSEUM NOVITATES NO. 3027

Fig. 5. Sphenomorphus cherriei (Cope), in life. A juvenile (AMNH 119063) from Rio Changuinola near Quebrada El Guabo, 200 m, Bocas del Toro lowlands on Atlantic side ofextreme western Panama; approximately x 2.7. known from the Atlantic side of extreme penes from several preserved Sphenomor- western Panama, from forest at an elevation phus cherriei. These partial eversions permit of200 m. It shows a curious mix ofcharacters comparisons between the basal (unbifurcat- but unfortunately is a small juvenile of only ed) halves ofthe hemipenes ofrarus and cher- 24 mm SVL: prefrontals present; rear margin riei. The cherriei examined included two from frontonasal nearly straight (slightly concave); Great Corn Island, off the Atlantic coast of anterior loreal absent; lower eyelid windows Nicaragua (AMNH 104422, 104424), and two single; midbody scale rows 28; paravertebral from La Selva, on the Atlantic side of Costa scale rows 55; rows between adpressed limbs Rica (CRE-USC 1055, 1555). about 8; 4th toe lamellae 15/14; 4th finger See figure 4 for the completely everted lamellae 8. hemipenis of S. rarus and the best eversion The presence of prefrontals and relatively obtained for S. cherriei. The asymmetrical high number of fourth toe lamellae seem to configurations ofthe lobes of the rarus hem- place this interesting specimen with S. cher- ipenis suggest the possibility of considerable riei, whereas the single palpebral disk (in < variation on this part of the organ; careful 1% ofcherriei), number ofparavertebral rows, field eversions (best done under magnifica- and absence ofthe anterior loreal are in agree- tion with a water-filled syringe) of a number ment with S. rarus. Radiographs ofthe hand of the relatively common cherriei might be and feet are unsatisfactory, being very poorly the easiest way of getting possible insight on resolved (presumably because some phalan- this point. Meanwhile, the material at hand ges are incompletely ossified). One interpre- indicates topographical constancy on the un- tation yields the hand/foot formulae of 2-3- bifurcated basal part of the hemipenis in 4-4-2/2-3-4-5-2, which, ifcorrect, is sugges- cherriei. tive of a third species in lower Central Amer- The hemipenes of S. cherriei and S. rarus ica. But not too much should be made of are generally similar but the basal part ofthe isolated juveniles, which sometimes show organs appear to differ in three respects: (1) variations not normally present in survivors In rarus the sulcus spermaticus divides below to adulthood. We provisionally assign this the crotch ofthe hemipenis (fig. 4A), whereas specimen to S. cherriei, which, because ofits it is essentially at the crotch in two cherriei proximity in Atlantic-side Costa Rica, was to in which the point of division could be seen be expected on the north coast of western (fig. 4B). (2) The transverse collarlike swelling Panama. A final judgment must wait for ad- below the hemipenial lobes in rarus has a ditional material. basal overhang that is relatively shallow and HEMIPENIS: Unsuccessful attempts were closely adherent to the body ofthe organ (fig. made to inflate incompletely everted hemi- 4A, A'). The homolog of this structure in 1991 MYERS AND DONNELLY: SPHENOMORPHUS 9 cherriei has a deeper and widely flared over- these (Echinosaura, Leposoma, Prionodac- hang, giving the organ a distinctly capitate tylus,6 and Ptychoglossus) cannot possibly be appearance (fig. 4B, B'). (3) As viewed from confused with Sphenomorphus because they the sulcate side, in S. rarus, the lateral basal have strongly keeled or tuberculate scales, expansions on the sulcate side (fig. 4A) are with the dorsals and ventrals differing in weakly swollen ridges that rise distally to be- shape. The three smooth-scaled genera, each come joined on the asulcate side by a weak with a single representative in western Pan- transverse ridge (fig. 4A'). The homolog in S. ama, can be easily distinguished from New cherriei is more pronounced, resulting in a World Sphenomorphus as follows: The ar- much stronger transverse asulcate ridge, from boreal Anadia (ocellata) has an exceedingly which a weaker ridge is produced distad to- long tail, lateral ocelli, and quadrangular dor- ward the capitate overhang (fig. 4B'). sal and ventral scales in transverse rows. The Thus, hemipenial differences between Pan- semifossorial Bachia (blairi) has hexagonal amanian Sphenomorphus rarus and Nicara- dorsal and quadrangular ventral scales and guan and Costa Rican S. cherriei seem to reduced limbs bearing fewer than five toes support our conclusion that the unique spec- (four on forefoot, three on hind foot). Gym- imen of rarus represents a different species. nophthalmus (speciosus) is the most skinklike PHALANGEAL FoRMuLAE: Differences in of the Panamanian microteiids, since it has number of phalanges also support the rec- smooth, shiny, dorsal and ventral scales that ognition of S. rarus. Comparisons of X-ray are imbricate and tending to be posteriorly photographs ofthe holotype and ofthree adult rounded. But it differs from Panamanian male S. cherriei from Costa Rica show S. skinks in numerous characters, including a rarus with one less phalanx in the fourth fin- low number (; 13-15) ofmidbody scale rows ger and one less in the fifth toe. The hand/ and four rather than five toes on the forefoot; foot formulae are otherwise the same, as fol- it also lacks movable eyelids. In this last char- lows (rarus in parentheses, where different): acter, Gymnophthalmus differs also from all 2-3-4-5(4)-3/2-3-4-5-4(3). other Panamanian microteiids.

COMPARISONS WITH OTHER LIzARDs EcoLoGIcAL GEOGRAPHY OF NEW WORLD The only other genus oftrue skinks in Pan- SPHENOMORPHUS AT THE SOUTHERN END ama is Mabuya, readily distinguished from OF THE RANGE all New World Sphenomorphus by larger size and the presence of supranasals and paired A few authors (e.g., Peters and Donoso- frontoparietals. Other shiny-scaled, skinklike Barros, 1970: 155) have listed cherriei as oc- lizards in Panama belong to the families An- curring south "to Panama." Stuart (1940: 5), guidae and Teiidae (microteiids only). A small without going into details, mentioned the ex- brown anguid, Diploglossus bilobatus, occurs istence of"a large series ofspecimens [of"L- microsympatrically with Sphenomorphus ygosoma assatum cherriei"] from Chiriqui in cherriei in Costa Rica and in the Atlantic Panama." Stuart evidently referred to the lowlands of western Panama (e.g., AMNH ANSP specimens obtained by E. R. Dunn 119015-16, from the same locality as the pe- and discussed above under Pacific Western culiar juvenile S. cherriei described above), Panama. Dunn (1931: 17) himself, however, but it differs in numerous respects, including in a probable lapse ofmemory, seems to have sheathed claws, supranasals, prefrontals in erred in listing "Leiolopisma assatum" from contact, a single large frontal (no frontonas- central Panama. Until recently, Dunn's ma- al), and small, paired frontoparietals. See Myers (1973) for a key to the three genera 6 This genus barely enters eastern Panama: Priono- and five species of anguids occurring in Pan- dactylus vertebralis is known only from 1400-1410 m ama. on Cerro Mali (AMNH 119368-70, KU 76174-75), and Seven diverse genera of microteiids are from 1540-1660 on Cerro Tacarcuna (AMNH 119367)- found on the Isthmus of Panama. Four of both localities very close to the Colombian border. 10 AMERICAN MUSEUM NOVITATES NO. 3027

Fig. 6. Western Panama, showing locality records for Sphenomorphus (sensu Greer) at the southern end of the New World range. terial from the Puerto Armuelles region on and farmland in the last halfcentury and was the Pacific side of extreme western Panama less extensive to begin with, being essentially seems to have been the only valid basis for a short eastward extension ofthe Golfo Dulce including cherriei in the Panamanian fauna. rain-forest region ofsouthwestern Costa Rica. The only additional Panamanian specimen Less suitable (drier) lowland habitat occurs of cherriei known to us is the juvenile spec- to the east of this region. imen tentatively assigned to that species from Sphenomorphus rarus extends the New the north coast. Based on these few records, World range ofthe genus south and east near- the range ofSphenomorphus cherriei extends ly to the 82nd meridian, in the central high- out of Costa Rica along both coasts into the lands of western Panama (fig. 6). The type lowlands of extreme western Panama (fig. 6); locality is on the Atlantic versant in lower it is a lowland rain-forest distribution. These montane rain forest at 780 m elevation. The southernmost records ofcherriei may well be one elevational record is equivocal: S. rarus near the terminus ofits range, although, based may prove to be a lowland species sampled on gross habitat, the range on the Atlantic near the upper end of its elevational range, coast might be expected to extend farther east although we suspect that it is an upland spe- along the foothills for another 100 km or so. cies. Various kinds of upland distributions In contrast, much of the lowland wet forest are represented by endemic elements of the on the Pacific side has been turned to pasture herpetofauna in the general region. For ex- 1991 MYERS AND DONNELLY: SPHENOMORPHUS I I ample, the poison frog Dendrobates speciosus (KU), and Dr. Jay M. Savage, Costa Rican occurs in a restricted area of wet forest at Expeditions collection (CRE), University of 1140-1410 m above sea level (Edwards et Miami. For reading the manuscript, we thank al., 1988), whereas D. arboreus, essentially a Drs. Allen E. Greer, Hobart M. Smith, and highland species, descends nearly to sea level Richard G. Zweifel. (Myers et al., 1984); both of these are locally abundant in a narrowly zoned east-to-west REFERENCES distribution. But Sphenomorphus rarus is Cope, Edward Drinker more reminiscent of the snake Hydromor- 1893. Second addition to the knowledge ofthe phus dunni, a valid species still known only Batrachia and Reptilia of Costa Rica. from the holotype collected halfa century ago Proc. Am. Philos. Soc. 31: 333-347.7 (Savage and Donnelly, 1988). Donnelly, Maureen A. The type locality of Sphenomorphus rarus 1989. Reproductive phenology and age struc- is little over 1 km north of a low section of ture of Dendrobates pumilio in north- the continental divide, where wet climatic eastem Costa Rica. J. Herpetol. 23: 362- conditions of the Atlantic versant spill over 367. Emmett into the upper valley of the Rio Chiriqui of Dunn, Reid 1931. Preliminary list of the reptiles and am- the Pacific side. Thus, the only known locality phibians of the Canal Zone and the for S. rarus lies essentially between the east- provinces of Panama and Colon, R. P. ern (southern) end of the Cordillera de Tal- In Thomas Barbour, Seventh annual re- amanca and the western end of the Serrania port ofBarro Colorado Island Biological de Tabasara (see Myers and Duellman, 1982: Laboratory, Panama Canal Zone, pp. 12-14, for geography of this region). It is an 15-18. Washington, D. C.: National Re- ambiguous point from which the distribution search Council (mimeographed 24-page might extend in either direction or both. report). Edwards, M. W., John W. Daly, and Charles W. Myers ACKNOWLEDGMENTS 1988. Alkaloids from a Panamanian poison frog, Dendrobates speciosus: identifica- The new lizard was collected in early 1983 tion of pumiliotoxin-A and allopumi- near what is now the transisthmian highway liotoxin class alkaloids, 3,5-disubstitut- from Gualaca on the Pacific side of Panama ed indolizidines, 5-substituted 8- to Chiriqui Grande on the Atlantic coast. The methylindolizidines, and a 2-methyl-6- Atlantic-slope side of this road, then being nonyl-4-hydroxypiperidine. J. Nat. built by Constructora Urbana, S.A. (CUSA), Products 51(6): 1188-1197. was at that time only a muddy bulldozer track. Greer, Allen E., Jr. For allowing access to the construction area, 1974. The generic relationships of the scincid and for use offacilities in CUSA road camps, lizard genus Leiolopisma and its rela- grateful acknowledgment is due Ing. Alberto tives. Australian J. Zool., suppl. ser. no. 31: 67 pp. Aleman III, Ing. Rafael Aleman, and Ing. Ed- 1979. Eremiascincus, a new generic name for gar Hernandez. The senior author's field- some Australian sand swimming skinks work, part of an ecological assessment of the (Lacertilia: Scincidae). Rec. Australian transisthmian oil pipeline, was greatly facil- Mus. 32(7): 321-338. itated by Dr. Pedro Galindo of the Gorgas Guyer, Craig Memorial Laboratory, Dra. Fiorella De Vi- 1986. Seasonal patterns of reproduction of centi de Ciniglio of Estudios Ambientales, Norops humilis (Sauria: Iguanidae) in S.A., and by Ing. Jose Arosema III, General Costa Rica. Rev. Biol. Trop. 34: 247- Manager of Petroterminal de Panama. Spe- 251. cial thanks to all. For access to specimens in their care, we 7There is some library evidence that this part of vol- are grateful to Mr. Edmond V. Malnate, ume 31 ofthe Proceedings did not appear until February Academy ofNatural Sciences ofPhiladelphia 1894, in which case new names in Cope's paper will date (ANSP), Dr. William E. Duellman, Univer- from a preprint to which the line has been added (bottom sity of Kansas Museum of Natural History p. 347) "Reprinted Dec. 30, 1893 . . ." 12 AMERICAN MUSEUM NOVITATES NO. 3027

Lieberman, Susan S. Savage, Jay M., and Maureen A. Donnelly 1986. Ecology of the leaf litter herpetofauna 1988. Variation and systematics in the colu- of a Neotropical rain forest: La Selva, brid snakes ofthe genus Hydromorphus. Costa Rica. Acta Zool. Mexicana 15: 1- Amphibia-Reptilia 9: 289-300. 72. Smith, Hobart M., and Edward H. Taylor Myers, Charles W. 1950. An annotated checklist and key to the 1973. Anguid lizards ofthe genus Diploglossus reptiles of Mexico exclusive of the in Panama, with the description of a snakes. Smithson. Inst., U.S. Natl. Mus. new species. Am. Mus. Novitates 2523: Bull. 199: vi + 253 pp. 20 pp. Stuart, L. C. 1982. Blunt-headed vine snakes (Imantodes) 1940. Notes on the "Lampropholis" group of in Panama, including a new species and Middle American Lygosoma (Scinci- other revisionary notes. Ibid., 2738: 50 dae) with descriptions oftwo new forms. pp- Occas. Pap. Mus. Zool., Univ. Michigan Myers, Charles W., and William E. Duellman 421: 16 pp. 1982. A new species ofHyla from Cerro Col- 1963. A checklist ofthe herpetofauna of Gua- orado, and other tree frog records and temala. Misc. Publ. Mus. Zool., Univ. geographical notes from western Pana- Michigan 122: 150 pp. + map. ma. Am. Mus. Novitates 2752: 32 pp. Taylor, Edward H. Myers, Charles W., John W. Daly, and Victor 1956. A review of the lizards of Costa Rica. Martinez Univ. Kansas Sci. Bull. 38, pt. 1 (1): 3- 1984. An arboreal poison frog (Dendrobates) 322. from western Panama. Am. Mus. Nov- Villa, Jaime, Larry David Wilson, and Jerry D. itates 2783: 20 pp. Johnson Peters, James A., and Roberto Donoso-Barros 1988. Middle American herpetology: a biblio- 1970. Catalogue ofthe Neotropical Squamata graphic checklist. Columbia: Univ. Part II. Lizards and amphisbaenians. Missouri Press, xxxvi + 131 pp. Smithson. Inst., U.S. Natl. Mus. Bull. 297: viii + 293 pp.

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