Part 3

_Diagnosis._--1) Size moderate, sexual dimorphism extreme; maximum observed snout-vent length in males 48.1 mm, in females 75.1 mm; 2) skin on dorsum in males bearing a mixture of large and small non-spinous tubercles; 3) skin on flanks, especially anteriorly, areolate; 4) web usually extending only to base of antepenultimate phalange on inner edge of third finger; 5) dorsum pale tan or green with irregular, longitudinal, dark brown blotches, usually narrowly outlined with cream; 6) venter cream or tan, suffused with brown or marked with brown spots in some specimens; 7) lips marked with vertical brown and cream bars; 8) flanks creamy tan with irregular brown spots and/or diagonal marks; 9) dermal roofing bones of skull lacking exostosis; 10) dermal sphenethmoid absent; 11) nasals widely separated medially; 12) anteromedial margin of frontoparietal at mid-level of orbit; 13) frontoparietal fontanelle partially exposed; 14) palatine serrate; 15) parasphenoid bearing odontoids; 16) zygomatic ramus of squamosal extending approximately one-half of distance to maxillary arch; 17) transverse processes of third presacral vertebra narrower than sacral diapophyses; transverse processes of presacral vertebrae 3-8 subequal in width and narrower in males than in females; 18) intermandibularis and submentalis muscles independent; 19) supramandibular portion of interhyoideus extensively developed; associated skin forming broad loose fold.

_Osteocephalus buckleyi_ can be distinguished readily from all other species in the genus by the presence of areolate skin anteriorly on the flanks and by the rather boldly contrasting dorsal pattern. Furthermore, females are distinctive in having tubercles on the eyelids and supratympanic folds.

_Distribution._--The periphery of the Amazon Basin, in the Guianas and Territorio do Amapá in northeastern Brasil; the upper Amazon Basin from southern Colombia to east-central Bolivia; one locality (Acevedo) in upper Río Magdalena drainage in Colombia (Fig. 8). All localities are at elevations of less than 700 m. Records for Pallatanga and Santiago in Provincia Chimborazo, Ecuador (high on the Pacific slopes of the Andes), are considered to be erroneous. 78 specimens from 40 localities.

_Remarks._--In life the dorsum is green with dark markings. A male (KU 123171) from Santa Cecilia, Ecuador, was: "Dorsum green with dark brown blotches. Anterior and posterior surfaces of thighs dull blue. Venter brown, flecked with white. Iris greenish bronze with brown horizontal triangles and ventromedian brown line." (W. E. Duellman, field notes, 16 June 1968.) A female (KU 126646) from Lago Agrio, Ecuador, was: "Dorsum pale green with darker green blotches and creamy yellow middorsal stripe. Lateral blotches bronze-tan. Flanks tan with black blotches. Anterior surfaces of thighs dark brown. Dorsal and posterior surfaces of thighs and shanks tan with dark brown blotches. Webbing brown. Suborbital spot green. Postorbital bar black. Belly grayish brown in appearance--tips of granules white; intergranular spaces brown. Iris golden bronze with black flecks peripherally and median, horizontal, reddish brown streak." (W. E. Duellman, field notes, 12 May 1969.)

No ontogenetic change in coloration has been noted.

=Osteocephalus leprieurii= (Duméril and Bibron)

_Hyla leprieurii_ Duméril and Bibron, 1841:553 [Holotype.--MNHN 4629 from "Cayenne"; Mons. Leprieur collector].

_Hypsiboas leprieurii_--Cope, 1867:200.

_Hyla leprieurii britti_ Melin, 1941:42 [Holotype.--NHMG 489 from the Rio Uaupés, north of the Rio Japu, Territorio do Amazonas, Brasil; Douglas Melin collector]. New synonymy.

_Hyla leprieurii leprieurii_--Melin, 1941:42.

_Osteocephalus britti_--Goin, 1961:13.

_Osteocephalus leprieurii_--Goin, 1961:13.

_Justification of Synonymy._--The holotype of _Hyla leprieurii_ is a female having a snout-vent length of 46.6 mm. The diameter of the tympanum is 3.7 mm, 69.8 percent of the diameter of the eye. The dorsal roofing bones are smooth, and the skin on the dorsum is smooth. The penultimate phalanges of the fingers are not included in the webbing. When we examined the specimen on 2 July 1969, it was slightly soft and somewhat faded to a peculiar grayish green color with faint darker transverse bars on the limbs. Duméril and Bibron (1841:554) described the coloration, as follows: "The loreal region is black. A stripe of the same color extends from the posterior border of the orbit to the corner of the mouth, passing through the tympanum. All of the dorsal parts are grayish white with large transverse brown bands, which are more expanded and less regularly outlined on the back than on the limbs. There is one of these on the occiput that is in a triangular shape. All of the venter is white." (Free translation from French.)

The holotype of _Hyla leprieurii britti_ is a male having a snout-vent length of 48.1 mm. The diameter of the tympanum is 3.6 mm, 65.5 percent of the diameter of the eye. The skin on the dorsum is tubercular; the tubercles are small on head and on the dorsal surfaces of the limbs and slightly larger on the back. The penultimate phalanges of the fingers are not included in the webbing. Melin (1941:43) stated: "Above blackish brown with a very indistinct band between the eyes; iris with mottle of metallic lustre; hinder parts of upper jaw whitish; sides of body mottled with blackish brown; hind limbs (especially tibiae and tarsi) with narrow, diffuse cross bars; beneath whitish with slight brown mottle along jaw." We examined the type on 17 February 1969; at that time it was dull brown above with faint, narrow, dark brown, transverse bars on the back and dorsal surfaces of the limbs. A cream subocular spot was evident, and the venter was creamy white.

Melin (1941:42) stated that the holotype of _Hyla leprieurii britti_ "... resembles a good deal _H. leprieurii_ Dum. & Bibr. As, however, it differs from the latter species by its very concave loreal region, small tympanum, and almost uniformly brownish colour, it may at least form a subspecies of _leprieurii_...." The pattern of narrow transverse bars on the backs of the holotypes of _H. leprieurii_ and _H. britti_ is a condition shared only by these two nominal taxa that are placed in _Osteocephalus_. Melin noted that _britti_ differed from _leprieurii_ in the depth of the loreal concavity and in the size of the tympanum. Neither of these differences is noteworthy in comparison with series of specimens. The depth of the loreal concavity is a highly subjective character, and we note no differences between the types. The ratio of the diameter of the tympanum to the diameter of the eye is relatively smaller in both holotypes (0.698 in _leprieurii_--[F]; 0.655 in _britti_--[M]) than in series of fresh specimens from Lago Agrio, Ecuador (0.652-0.884, mean 0.785 in 17 males; 0.700-0.909, mean 0.790 in 20 females). The smaller proportions in the types may be due to geographic variation or to shrinkage as a result of many years in preservative (130+ years for _leprieurii_; 45 for _britti_).

Comparisons of the holotypes with series of specimens from Ecuador, Guyana, and Surinam indicate that one morphological species occurs throughout the upper Amazon Basin and the Guianas and that both type specimens are representatives of one species. Consequently, we consider _Hyla leprieurii_ Duméril and Bibron, 1841, to be a monotypic species with _Hyla leprieurii britti_ Melin, 1941, as a junior synonym.

In their account of _Osteocephalus leprieurii_, Cochran and Goin (1970:323) stated: "The specimen described and illustrated (MCZ 28042) has been directly compared with the types of _leprieurii_, _planiceps_, and _vilarsi_ by the junior author and there seems to be no doubt that all are conspecific. Another specimen (CNHM 69716) has been directly compared with the types of _planiceps_ and _vilarsi_ and these, likewise, are considered conspecific." With this justification Cochran and Goin (1970:322) included _Osteocephalus planiceps_ Cope, 1874, and _Hyla vilarsi_ Melin, 1941, in the synonymy of _Osteocephalus leprieurii_.

We do not concur with Cochran and Goin's synonymy and contend that _planiceps_ and _vilarsi_ are synonyms of _Osteocephalus taurinus_; we give our reasons in the account of that species. We have examined the specimens listed as _O. leprieurii_ by Cochran and Goin; several of them, including CNHM (= FMNH) 69716, are _taurinus_. Thus, due to Cochran and Goin's confusion of two taxa, their comparisons of certain specimens with types has little meaning.

Cochran and Goin did not include _Hyla leprieurii britti_ in their synonymy of _Osteocephalus leprieurii_ but did discuss the name in their account of _Osteocephalus orcesi_ (= _O. verrucigerus_), as follows (1970:319): "When we first examined one of the specimens we felt sure that we had Melin's _Hyla britti_ at hand, but on direct comparison with the type of _britti_ the two proved to be different. After studying the type of _orcesi_ (SUNHM 13150) we have no doubt that the specimens at hand are _orcesi_ and that _britti_ is a different, probably valid species."

_Diagnosis._--1) Size moderate, sexual dimorphism evident; maximum observed snout-vent length in males 48.4 mm, in females, 61.5 mm; 2) skin on dorsum in males bearing numerous, minute, spinous tubercles; 3) skin on flanks smooth; 4) web extending to base of antepenultimate phalange on inner edge of third finger; 5) dorsum tan or olive-brown with transverse brown or olive bars; 6) venter creamy white or pale tan without markings; 7) lips marked with creamy tan labial stripe and suborbital spot; 8) flanks pale tan with no markings; 9) dermal roofing bones of skull lacking exostosis; 10) dermal sphenethmoid absent; 11) nasals juxtaposed medially; 12) anteromedial margin of frontoparietal between mid- and anterior levels of orbit; 13) frontoparietal fontanelle partially exposed; 14) palatine not serrate; 15) parasphenoid lacking odontoids; 16) zygomatic ramus of squamosal extending about one-half of distance to maxillary arch; 17) transverse processes of presacral vertebrae 3-8 about equal in width to one another and to sacral diapophyses; 18) intermandibularis and submentalis muscles connected; 19) supramandibular portion of interhyoideus forming simple tubular posterolateral extension; associated skin unmodified.

_Osteocephalus leprieurii_ differs from all other members of the genus by having transverse dark bars on the back. Two other hylids (_Hyla lanciformis_ and _multifasciata_) in the Amazon Basin have transverse dark marks on the dorsum. Both of these differ from _leprieurii_ by having pointed snouts, much longer hind limbs, and smooth skin dorsally.

_Distribution._--The periphery of the Amazon Basin, in the Guianas and the upper part of the basin in southern Colombia, Ecuador, Perú, and extreme western Brasil (Fig. 9). Most localities are at elevations of less than 500 m, but the species ascends the lower Andean slopes to elevations of 1100 m. 265 specimens from 31 localities.

_Remarks._--Most adults of _leprieurii_ have distinct transverse markings on the back; these are variable in width, extent, and arrangement. In some specimens, such as USNM 166557, some of the transverse bars are fragmented into spots; in a few specimens the dorsal pattern consists solely of small dark spots arranged in transverse rows. Such specimens have a dorsal pattern resembling that of some _taurinus_. The transverse nature of the dorsal markings is further modified in some specimens, such as USNM 166555, in which the dark bars are fragmented and oblique.

Extreme ontogenetic change in color pattern is exhibited by this species (Fig. 10). Juveniles having snout-vent lengths of less than 28 mm have an olive-brown dorsum with a pale cream stripe across the head and broad, cream, dorsolateral stripes; transverse dark bars are absent on the body and limbs. Individuals having snout-vent lengths of 30-35 mm have dark brown transverse bars on the back and limbs but still retain the light dorsolateral stripes, whereas the stripes are lost in larger individuals.

Coloration in life of specimens from Lago Agrio, Ecuador: "In males the dorsal ground color varies from dark brown to ochre-tan; dorsal markings uniformly dark brown. Most specimens have dark brown and cream anal stripes; labial area cream-colored. Flanks vary from tan to white. Ventral coloration varies from salmon to tan to white. The iris is bronze with a greenish cast and black reticulations. In females the dorsal coloration is the same as in males, except that dark marks tend to be outlined with cream; venter tannish salmon." (W. E. Duellman, field notes, 12 May 1969).

=Osteocephalus pearsoni= (Gaige)

_Hyla pearsoni_ Gaige, 1929:3 [Holotype.--UMMZ 57548 from the upper Río Beni, below mouth of Río Mapiri, Departamento El Beni, Bolivia; N. E. Pearson collector].

_Osteocephalus pearsoni_--Goin, 1961:13.

_Justification of Synonymy._--Goin (1961:13) suggested that _Hyla pearsoni_ Gaige was an _Osteocephalus_, but Cochran and Goin (1970:217) considered _pearsoni_ to be a _Hyla_. The presence of exostosed dermal roofing bones, angulate prevomerine dentigerous processes, and the structure of the vocal sacs are characters which place the species in _Osteocephalus_.

_Diagnosis._--1) Size moderate, sexual dimorphism evident; maximum observed snout-vent length in males 46.2 mm, in females 54.7 mm; 2) skin on dorsum in males bearing a few, small, scattered non-spinous tubercles; 3) skin on flanks smooth; 4) web extending to base of antepenultimate phalange on inner edge of third finger; 5) dorsum tan with irregular brown blotches; 6) venter cream with fine brown reticulations; 7) lips dark with pale vertical bar below eye; 8) flanks pale tan with round, brown spots; 9) dermal roofing bones of skull slightly exostosed; 10) dermal sphenethmoid absent; 11) nasals narrowly separated medially; 12) anteromedial margin of frontoparietal between mid- and anterior levels of orbit; 13) frontoparietal fontanelle covered; 14) palatine not serrate; 15) parasphenoid lacking odontoids; 16) zygomatic ramus of squamosal extending about one-half distance to maxillary arch; 17) transverse processes of third presacral vertebra approximately equal in width to sacral diapophyses; transverse processes of presacral vertebrae 3-8 subequal in width; 18) intermandibularis and submentalis muscles connected; 19) supramandibular portion of interhyoideus extensively developed; associated skin forming broad loose fold.

_Osteocephalus pearsoni_ can be distinguished most readily from other members of the genus by the brown reticulate pattern on the venter, round brown spots on the flanks, and smooth skin on the flanks. Also, it is the least tuberculate species in the genus.

_Distribution._--Upper Amazon Basin and Amazonian slopes of the Andes in central Perú (1620 m in Río Ucayali drainage) and northern Bolivia (less than 500 m in Río Beni drainage) (Fig. 8). 6 specimens from 3 localities.

_Remarks._--The specimen from Yaupi, Perú (KU 136312) is a subadult female having a snout-vent length of 39.8 mm. In life the coloration was: "Dorsum light pinkish brown with large rich chocolate brown blotch from eyes to anterior tips of ilia; numerous small chocolate blotches on flanks; dorsal surfaces of thighs and shanks, canthus, and supraorbital region to insertion of forearm chocolate brown; supralabial border and short bar from eye to lip bronze-white; venter bronze-white with numerous tiny chocolate brown flecks [tending to form reticulations on throat and chest]; anterior and posterior surfaces of thighs light olive-brown; iris largely black with gold flecks." (Thomas H. Fritts, field notes, 23 March 1970.) On the basis of this one subadult, it seems likely that reticulations on the venter develop with age.

=Osteocephalus taurinus= Steindachner

_Osteocephalus taurinus_ Steindachner, 1862:77 [Holotype.--NHMW 16492 from Barra do Río Negro, Manáus, Territorio do Amazonas, Brasil; Johann Natterer collector].

_Osteocephalus flavolineatus_ Steindachner, 1862:80 [Holotype.--NHMW 16495 from Cucuí, Territorio do Amazonas, Brasil; Johann Natterer collector].

_Trachycephalus (Osteocephalus) taurinus_ Steindachner, 1867:64.

_Osteocephalus planiceps_ Cope. 1874:122 [Holotype.--ANSP 11399 from Nauta, Departamento de Loreto, Perú; James Orton collector]. New synonymy.

_Hyla taurina_--Boulenger, 1882:363 [synonymized _Osteocephalus flavolineatus_ Steindachner, 1862, with _O. taurinus_ Steindachner, 1862].

_Hyla planiceps_--Boulenger, 1882:364.

_Hyla (Trachycephalus) vilarsi_ Melin, 1941:40 [Holotype.--NHMG 488 from Taracuá, Río Uaupés, Territorio do Amazonas, Brasil; Douglas Melin collector]. (_fide_ Bokermann, 1966:64.)

_Hyla depressa_ Andersson, 1945:73 [Holotype.--NHRM 1966 from the Río Pastaza watershed (? Provincia Pastaza), Ecuador; William Clarke-MacIntyre collector]. New synonymy.

_Justification of Synonymy._--The holotype of _Osteocephalus taurinus_ is a female having a snout-vent length of 103.9 mm. The diameter of the tympanum is 6.8 mm, 77.3 percent of the diameter of the eye. The skull is strongly exostosed, and the lateral edges of the frontoparietals are elevated so as to form distinct ridges. The skin on the dorsum is smooth. When we examined the type on 5 August 1969, the specimen was soft and badly faded to a pale creamy tan with pale brown transverse bars on the hind limbs and spots on the flanks. Steindachner (1862:79) described the coloration of the type: "In the preserved specimen the dorsum of the entire body, including fore and hind limbs, is a light yellow-brown color, which becomes lighter towards the venter. The belly is whitish, as are the undersides of the arms and legs. The throat is indistinctly marbled with brown. Roundish dark brown flecks are randomly distributed in a considerable number along the side of the body up to the eye; the tympanum is more or less fully surrounded by brown. A few discrete spots, always more or less drawn out in length, on the sides of the body, are also found on the posterior part of the back. The dorsal surfaces of the fore and hind feet are marked with somewhat obliquely arranged brown transverse bands, which are more intensively colored near the margin than in the middle of the band." (free translation from German.)

The holotype of _Osteocephalus flavolineatus_ is a female having a snout-vent length of 81.8 mm. The diameter of the tympanum is 6.0 mm, 71.4 percent of the diameter of the eye. The skull is strongly exostosed, and the lateral edges of the frontoparietals are elevated so as to form a ridge on each side. The skin on the dorsum is very weakly tuberculate. We examined the type on 9 August 1969 and found it to be in excellent condition. The color pattern is unchanged from that described by Steindachner (1862:81). The dorsum is tan with irregular brown blotches on the back, spots on the flanks, and transverse bars on the limbs. A narrow creamy white, middorsal stripe extends from the snout to the vent. The subocular area is creamy tan, and the venter is tan. Boulenger (1882:363) questionably synonymized _flavolineatus_ with _taurinus_. We have observed that a middorsal cream stripe occurs in about 10 percent of the specimens of _taurinus_ and in some specimens of _buckleyi_. This is a common color morph in many species of _Eleutherodactylus_. In the absence of distinguishing morphological characteristics we can only conclude that the middorsal stripe is a pattern variant and that Boulenger was correct in synonymizing _flavolineatus_ with _taurinus_.

The holotype of _Osteocephalus planiceps_ is a male having a snout-vent length of 58.5 mm. The diameter of the tympanum is 4.9 mm, 77.8 percent of the diameter of the eye. The skull is moderately exostosed, and the lateral edges of the frontoparietals are distinctly elevated. The skin on the dorsum is tuberculate. Cope (1874:122) described the coloration of the type as follows: "Color above uniform dark brown, concealed surfaces on the limbs similar and without any markings. Sides a little varied with the white of the belt. A light border to the upper lip, and lighter line from the orbit to the angle of the mouth; dermal scapular fold pale edged. Femur and tibia with dark crossbands on the exposed surfaces." We examined the holotype on 25 September 1969, and found it to be soft and rubbed. The coloration remains much the same as described by Cope, who provided no means of distinguishing _planiceps_ from _taurinus_. The coloration and morphometric and structural characters of the type of _planiceps_ all fall within the range of variation displayed by series of _O. taurinus_ from the upper Amazon Basin.

The type of _Hyla vilarsi_ is a gravid female having a snout-vent length of 62.7 mm. The diameter of the tympanum is 4.8 mm, 73.8 percent of the diameter of the eye. The dorsal roofing bones of the skull are moderately exostosed, and the lateral edges of the frontoparietals are distinctly elevated. The skin on the dorsum is smooth. Melin (1941:42) described the coloration of the holotype as follows: "Above uniform reddish brown; upper eyelids and sides of head darkish brown; below the rostral edge a narrow dark band, continuing as a broader light-edged one through the eye and tympanum towards the base of the forelimb and then farther on continuing along the sides as a line of black spots; sides of upper jaw whitish with traces of dark cross bars (one distinct under the eye); sides of body darkish with black spots and marble, often on a whitish ground; thighs, tibiae, and tarsi each with two broad light-edged, dark cross bars on a brownish ground (less distinct on thighs); sides of thighs finely mottled with brown; beneath whitish with small, sparse spots along jaw, on the chest and sides." We examined the type on 17 February 1969, at which time the specimen was somewhat desiccated, especially the hands and feet. The coloration remains much the same as described by Melin, except that he failed to note the presence of four elongate spots on the back.

The status of the names _Osteocephalus planiceps_ Cope and _Hyla vilarsi_ Melin was confused by Cochran and Goin (1970:322), who assigned these names to the synonymy of _O. leprieurii_. Bokermann (1966:64) placed _Hyla vilarsi_ in the synonymy of _Osteocephalus taurinus_ without justification. The type specimens of both _planiceps_ and _vilarsi_ have moderately exostosed dermal roofing bones and distinct cranial ridges. The type of _planiceps_ has moderately large tubercles on the dorsum, and the type of _vilarsi_ has spots on the throat, chest, and flanks and longitudinal markings on the back. All of these features are characteristic of _taurinus_ and not of _leprieurii_, which lacks exostosis and cranial ridges and has transverse markings on the back, no spots on the throat, chest, and flanks, and in males has small dorsal tubercles.