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When we started a study of the reptiles and amphibians at Santa Cecilia in Amazonian Ecuador in 1966, we quickly faced many types of animals that we couldn't identify using the available literature. Comparing our specimens with those stored in other museums helped solve some of the issues, but many identifications could only be made after examining type specimens; even then, some determinations remained uncertain. We now realize that to create a meaningful account of the herpetofauna of Santa Cecilia, we need to complete several taxonomic studies that extend well beyond eastern Ecuador. Due to our interest in hylids, we have begun our research on these frogs.

One of us (Trueb, 1970a) studied the skull structure of casque-headed hylid frogs and redefined the genus Osteocephalus but did not determine how many species are in the genus. Our research in Amazonian Ecuador led to the discovery of three species occurring together at two locations; one of these species was found with a fourth species at a different location. Examining museum specimens confirmed the identification of these four species in the Amazon Basin and the lower Amazonian slopes of the Andes. A fifth species from Bolivia and Peru is also included in the genus. Looking at museum specimens has provided information on the geographic variation and distribution of the five species. However, our conclusions about some populations need support, as we've faced challenges due to insufficient material from areas outside of Ecuador. More than half of the 905 specimens of Osteocephalus are from Ecuador, which is a relatively small portion of the total range of the genus.

In this paper, we present a taxonomic review of the genus Osteocephalus; our study has focused on the alpha level. We have used all the usual external characteristics, as well as osteological features, in our definitions of the species. Tadpoles and mating calls are known for only one species, O. verrucigerus (Trueb and Duellman, 1970); these and other important systematic features, like karyotypes, are currently unavailable for the group. We have generally taken a conservative approach to defining species; therefore, it's unlikely that any future researcher will identify fewer species within the genus. Our observations of these frogs in Amazonian Ecuador are detailed in the final section of this paper.

For lending specimens or providing workspace in their respective institutions, we owe thanks to James E. Böhlke, Werner C. A. Bokermann, F. W. Braestrup, Nelly Carrillo de Espinoza, Osvaldo R. da Cunha, Josef Eiselt, M. J. Fouquette, Jr., Alice G. C. Grandison, Jean Guibé, Birgitta Hansson, Walter Hellmich, M. J. Hoogmoed, Robert F. Inger, Konrad Klemmer, Jean Lescure, Alan E. Leviton, Clarence J. McCoy, Robert H. Mount, Charles W. Myers, Umberto Parenti, Günther Peters, James A. Peters, William F. Pyburn, Juan A. Rivero, Dorothy M. Smith, Paulo E. Vanzolini, Greta Vestergren, David B. Wake, Charles F. Walker, Ernest E. Williams, and Richard G. Zweifel.

The study of specimens in European museums was made possible by a grant (No. 5063) from the Penrose Fund of the American Philosophical Society. Fieldwork in Ecuador was partially supported by grants from the Watkins Fund of the Museum of Natural History at the University of Kansas. At our base camp in Santa Cecilia, Ecuador, we enjoyed the hospitality of Ing. Ildefonso Muñoz B. Transportation in Ecuador was generously provided by the Texaco Petroleum Company. During our fieldwork, Stephen R. Edwards and Thomas H. Fritts directly contributed to our study of Osteocephalus. Michael J. Tyler from the South Australian Museum provided information on the vocal sac structure. We sincerely thank all of these individuals for their contributions to our efforts.

We’ve looked at 893 preserved frogs, including the type specimens of all the nominal taxa, 8 skeletons, 1 lot of eggs, and 3 lots of tadpoles that we classify under the genus Osteocephalus; additionally, skulls were taken from five preserved specimens, and radiographs were made of 12 other preserved specimens. We’ve been lucky to observe living individuals of every species except O. pearsoni, but we do have color photos of a living specimen of that species. Figures 1 and 2 were created from projected color transparencies of living frogs. The terminology used follows Duellman (1970b). In the distribution maps, solid symbols indicate locations from which we have examined specimens; open symbols show other locality records from the literature. Throughout the text, specimens are listed by their catalogue numbers, preceded by the appropriate museum abbreviation, as follows:

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Because of the taxonomic confusion around the generic name Osteocephalus and two of the species (and their synonyms), we provide a brief summary of the taxonomic history of the group.

Among the amphibians sent to the Muséum National d'Histoire Naturelle in Paris by a Monsieur Leprieur in French Guiana was a single female specimen of a moderately large hylid with a well-ossified skull and smooth dorsal skin. This specimen escaped the eager attention of Johann Tschudi, who prematurely named several species based on specimens in Paris, and remained nameless until Duméril and Bibron (1841) proposed the name Hyla leprieurii for it. The species description is quite detailed, but the specimen was not illustrated. This is the earliest trivial name now associated with Osteocephalus.

Fitzinger (1843), in his overview of amphibians and reptiles, introduced the generic name Osteocephalus but didn’t link it to any specific species. As a result, Osteocephalus Fitzinger, 1843, is considered a nomen nudum. Franz Steindachner succeeded Leopoldo Fitzinger at the Naturhistorisches Museum in Vienna, where he had access to Fitzinger's notes and the significant collections in that museum. In 1862, Steindachner named two species of Osteocephalus based on Brazilian specimens collected by Johann Natterer. Both species were listed in the same publication; O. taurinus appeared on page 77, and O. favolineatus on page 80. This was the first time the generic name Osteocephalus was linked to a specific name and description, both of which meet the Code of Zoological Nomenclature for generic availability. Therefore, Steindachner is recognized as the authority for the generic name Osteocephalus, with O. taurinus designated as the type species. It is unclear whether Steindachner's use of Osteocephalus matched Fitzinger's intent from 19 years earlier.

Steindachner (1862) provided fairly accurate descriptions of his two new species and included excellent illustrations of both specimens, which were large females. Clearly intrigued by the similarities between Trachycephalus nigromaculatus Tschudi, 1838, and [Pg 5] Osteocephalus taurinus, Steindachner (1867) referred to the species as Trachycephalus (Osteocephalus) taurinus. This unclear terminology from the 1860s makes it impossible to determine whether Steindachner was effectively synonymizing Osteocephalus with Trachycephalus or if he was assigning Osteocephalus a subgeneric classification. Steindachner (1867) did not mention O. flavolineatus; perhaps by then he had decided that flavolineatus was just a color variation of taurinus.

Cope (1867) classified Hyla leprieurii under the genus Hypsiboas Wagler, 1830. In 1874, Cope described Osteocephalus planiceps from Nauta, Peru. The only specimen was part of the collections gathered by the Orton Expedition to the upper Amazon Basin and was stored at the Academy of Natural Sciences in Philadelphia.

Boulenger (1882) classified both Osteocephalus and Trachycephalus as synonyms of Hyla; he identified Hyla taurina (with O. flavolineatus as a synonym), H. leprieurii, and H. planiceps. In the same publication, Boulenger introduced Hyla buckleyi based on 10 specimens in the British Museum from Ecuador; in the description, he noted that buckleyi resembled leprieurii and taurinus due to its paired lateral vocal sacs. Boulenger's impact on taxonomic herpetology was significant, and his classification of Osteocephalus remained largely unchallenged until only a decade ago.

Goin (1961) provided a general overview of the hylid frog genera, identifying Osteocephalus and stating: "There are probably eight or ten species of this genus in South America. Definitely taurinus, britti, leprieuri, buckleyi, and pearsoni belong here. O. planiceps is likely a synonym of leprieuri, and I think garbei is too. The status of forms like macrotis, riopastazae, and depressa has not been resolved yet." Goin described Osteocephalus as follows: "Males have paired vocal pouches, one at each angle of the jaw; the skin of the head is not fused with the skull, but the roof of the skull has growths." Trueb (1970a) expanded on Goin's definition and included only O. taurinus and O. leprieurii in the genus.

Goin's inclusion of buckleyi, britti, and pearsoni in Osteocephalus was the first time any of these names were associated with that genus. Duellman (1970a) showed that Garbeana garbei Miranda-Ribeiro, 1926, is a part of the Hyla rubra group. Hyla macrotis Andersson, 1945, belongs to Phrynohyas. Trueb and Duellman (1970) identified Hyla verrucigera Werner, 1901, as the earliest name for an Osteocephalus that exhibits notable sexual dimorphism in the coloration and texture of its dorsal skin; Hyla riopastazae Andersson, 1945 (female holotype) and Hyla orcesi Funkhouser, 1956 (male holotype) were classified as synonyms of Osteocephalus verrucigerus.

Hyla pearsoni Gaige, 1929, is a small species of Osteocephalus. Our findings support Goin's suggestions regarding two other taxa. Hyla leprieurii britti Melin, 1941, from the Rio Uaupés, Brazil, and Hyla depressa Andersson, 1945, from the Río Pastaza watershed, Ecuador, are part of the genus Osteocephalus, but both are synonyms of earlier names—leprieurii and taurinus, respectively. Another name proposed by Melin (1941), Hyla (Trachycephalus) vilarsi from Taracuá, Brazil, is also considered a synonym of O. taurinus.

Cochran and Goin (1970) didn't know the identities of Hyla verrucigera and riopastazae; they used the later name Osteocephalus orcesi for Colombian frogs that should be referred to as O. verrucigerus. While Goin (1961) put Hyla buckleyi and H. pearsoni in Osteocephalus, Cochran and Goin (1970) identified a "buckleyi group" in Hyla that included these two species along with a new species, Hyla cabrerai from Amazonian Colombia and Brazil (a total of three specimens). Additionally, these authors named Hyla carri based on a single Colombian specimen. Research on the types of Hyla cabrerai, H. carri, and H. festae Peracca, 1904, from Ecuador shows that all these names are synonyms of Osteocephalus buckleyi.

Much of the confusion in classification and the numerous common names comes from the significant color variations in taurinus and the differences between male and female skin texture in all species. The specifics of these variations and our reasons for the synonym names are explained in the species accounts. All the common names for species recognized here as part of the genus Osteocephalus are listed in table 1.

Diagnostic Definition.—1) Skull wider than long; 2) skull's dermal roofing bones well-developed, with bony growths, and/or fused in some species; 3) prenasal and internasal bones missing; 4) parasphenoid wings oriented toward the back and sides; 5) dentigerous processes of prevomers angular (/— —); 6) paired vocal sacs located at the back, which protrude down and to the side when inflated; 7) submentalis muscle moderate in size and lacking a distinct form; 8) intermandibularis muscle not specialized and has an elongated [Pg 7] central aponeurosis; 9) parotoid glands either absent or poorly formed, skin does not secrete the thick mucous typical of Phrynohyas; 10) males have bumpy skin on their backs, while females have smooth skin; 11) tympanum large, at least 60 percent of eye diameter; 12) fingers about one-third webbed, toes more than three-fourths webbed; 13) discs are large and round; 14) breeding males have nuptial pads; 15) inner metatarsal tubercle not adapted for digging; 16) outer metatarsal tubercle is absent; 17) tarsal fold weak or not present; 18) pupil is horizontal; 19) eyelids are clear; 20) known tadpoles have two upper rows and five lower rows of teeth.

Content.—As defined here, the genus includes five known species: O. buckleyi (Boulenger), O. leprieurii (Duméril and Bibron), O. pearsoni (Gaige), O. taurinus Steindachner, and O. verrucigerus (Werner).

Distribution.—The Guianas and Amazon Basin; also in the upper Orinoco and Magdalena drainages. Most locations are at elevations below 500 m, but the genus can be found climbing the Amazonian slopes of the Andes to heights of about 1800 m.

Size and Proportions.—Frogs from the genus Osteocephalus are moderate to large hylids. The biggest species is taurinus, reaching a snout-vent length of 103.1 mm; the smallest is pearsoni, which grows to a length of 54.7 mm. There is a lot of variation in adult size within the same species, particularly in taurinus. Females of all species are noticeably larger than males, but there are no significant differences in proportions (Table 2).

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Coloration.—All Osteocephalus are mostly brown frogs, typically featuring some darker markings on their backs (Figs. 1 and 2). Osteocephalus verrucigerus has a nearly solid dark brown back and no visible transverse bars on its limbs, while all the other species have distinct bars on their limbs. The markings on the body vary, with irregular blotches in buckleyi, pearsoni, and taurinus, but narrow transverse lines in leprieurii. Some individuals of buckleyi and taurinus have a narrow cream or yellow stripe down the middle of their backs, which is not found in any of the other species. The sides are a consistent pale tan in leprieurii and a uniform reddish brown in verrucigerus; in the other species, the flanks range from cream to brown with dark brown or black spots (including dark diagonal marks in some buckleyi). Some specimens of leprieurii have a creamy white stripe around the anal area, but this is absent in all other species.

The area behind the eyes, which includes the eardrum, is dark brown in most specimens. In adult pearsoni and taurinus, the upper lips are dark brown. A light cream or tan spot under the eyes is found in pearsoni and in some taurinus; in certain specimens of taurinus, this spot extends backward, creating a stripe on the back part of the lip. The lip markings of verrucigerus follow a similar pattern, but in females, there is a clear, light stripe that runs the full length of the lip. Osteocephalus leprieurii features a broad, pale stripe on the lip. In buckleyi, the lips show a pattern of cream and dark brown bars.

The underside is consistently a creamy white or light tan in leprieurii, all white in some buckleyi (mostly males), and uniformly tan in some taurinus. The other species, along with some individuals of taurinus and buckleyi (mostly females), display dark markings on their undersides. These markings are especially prominent in verrucigerus, where the underside is white with striking black mottling and spots (Fig. 3c). Individuals of taurinus that have markings typically feature faint, scattered brown spots on the throat and chest (Fig. 3b). Osteocephalus pearsoni is noted for its fine brown pattern on the underside and on the front and back surfaces of the thighs in adults (Fig. 3a). Individuals of buckleyi that exhibit markings show a range of patterns found in pearsoni and taurinus (Figs. 3b and c).

Ontogenetic changes in coloration are minimal or absent in buckleyi, pearsoni, and taurinus, except that juveniles do not have ventral markings. A dark blotch on the back and clear transverse bars on the limbs can be seen in juvenile verrucigerus; these markings fade in adults. Juveniles of leprieurii are olive-brown with yellow dorsolateral stripes; the transverse dark marks, which are typical in adults, appear before the stripes fade away.

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Skin.—The dorsal skin of all male Osteocephalus has a bumpy texture to varying extents, while the dorsal skin of females is smooth, or almost smooth (Fig. 4). Osteocephalus verrucigerus stands out from other species in the genus due to its numerous large tubercles with keratinized tips. The tubercles on leprieurii are many and spiny, but significantly smaller than those on verrucigerus; taurinus has spiny tubercles as well, but in lower numbers compared to leprieurii. Osteocephalus buckleyi exhibits a mix of large and small, non-spiny tubercles, while pearsoni has only a few small, scattered, non-spiny tubercles. In females of buckleyi, fleshy tubercles are found on the eyelids and the supratympanic fold; females of pearsoni have a few small tubercles on their backs, while the dorsal skin of females from other species is smooth. The skin on the sides of both male and female buckleyi is slightly areolate; in the other species, the flanks are smooth. The skin on the top of the head in taurinus is rough due to co-ossification. In all species, the anal opening points backward at the upper level of the thighs.

Hands and Feet.—The feet of Osteocephalus are fully webbed or [Pg 13] almost fully webbed. The webbing between fingers one and two is present in all species. The webbing between fingers two, three, and four is most extensive in taurinus, where the three fingers are about half-webbed (Fig. 5). Osteocephalus buckleyi, pearsoni, and verrucigerus have reduced webbing between fingers two and three, and leprieurii has reduced webbing between fingers two, three, and four. All species in the genus have well-developed subconical subarticular tubercles on their fingers and toes; there's a tendency for the distal tubercle on the fourth finger to be slightly bifid. Palmar and plantar supernumerary tubercles are well developed in taurinus, moderately developed in buckleyi, leprieurii, and pearsoni, and barely noticeable in verrucigerus. All species show a noticeable fold on the wrist and enlarged prepollices that carry horny nuptial excrescences in breeding males. The prepollex is least enlarged in buckleyi. Outer metatarsal tubercles are absent. The inner metatarsal tubercle is moderately well developed and oval in leprieurii and pearsoni; it is elliptical and flat in the other species. Tarsal folds are absent in all species except verrucigerus, where the folds are barely noticeable.

Cranium.—As a group, the cranial structure is quite uniform and general when looked at within the family Hylidae. The skulls are wide and relatively flat, generally being a bit wider than they are long and about one-third as high as they are long. From a top view, the snouts are broadly rounded; however, the snout of buckleyi is somewhat less rounded and appears to be slightly longer than the snouts of other species. This subtle difference is linked to the relatively narrow premaxillaries in buckleyi.

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The genus is marked by well-developed dermal roofing bones and a notably large exposure of the sphenethmoid on the top (Fig. 6). The shape of the exposed sphenethmoid is determined by the positions of the nearby overlapping elements—the nasals and frontoparietals. The nasals overlap the outer edges of the sphenethmoid. Toward the front and middle, the nasals come together in leprieurii and taurinus, are closely spaced in buckleyi and pearsoni, or are more widely spaced in verrucigerus. In all species, the nasals end at the front top corner of the eye socket. The frontoparietals of buckleyi, leprieurii, and taurinus have an extension that overlaps the upper side edge of the sphenethmoid and connects with the back top corner of the nasal bone in buckleyi and taurinus; the bones are closely spaced in leprieurii. The frontoparietals of pearsoni and verrucigerus show more significant middle ossification and less front-side ossification. As a result, in those species, the back-middle part of the sphenethmoid is hidden, and the side edges are partially visible. The frontoparietal fontanelle is completely covered in all species, except buckleyi and leprieurii, where an irregular space between the frontoparietals reveals a small part of the fontanelle. The back side margins of the frontoparietals are located medial to the epiotic eminences.

Dermal ornamentation, involving the nasal bones, frontoparietal bones, and sphenethmoid, occurs in taurinus and, to a limited degree, in pearsoni. In the latter species, the outer edges of the frontoparietals, the upper surfaces of the nasals, and the back part of the exposed sphenethmoid show slight bumps, creating an open, net-like pattern of dermal sculpturing with very low relief (Fig. 6c). Osteocephalus taurinus is noted for its casing, co-ossification, and a complex pattern of dermal sculpturing, which was detailed and illustrated by Trueb (1970a).

The squamosals in all species are fairly large structures with otic plates that cover the side part of the cristae paroticae. The back rami are short, and the zygomatic rami of all species, except for taurinus, extend just over half the distance to the maxillary. In taurinus, the zygomatic ramus nearly reaches or connects to the maxillary.

The maxillary arches are fully formed and fairly strong. The alary processes of the premaxillaries are oriented vertically in leprieurii, pearsoni, and taurinus, and are slightly tilted backward in buckleyi and verrucigerus. The maxillaries consistently lack postorbital processes and have preorbital processes that connect with the maxillary processes of the nasals. The facial parts of the maxillaries are moderately developed in all species except for taurinus, where the facial part tends to connect with the side edge of the nasal in well-boned individuals. The palatine parts are underdeveloped in all species except for buckleyi, where the palatine part of the premaxillary is moderately strong.

The pterygoids are consistently shaped like a three-pronged fork. The front branches end around the middle of the eye socket, and the inner branches connect firmly with the front corner of the ear capsule. The palatines are well-formed structures with ridges on the underside; these ridges are somewhat uneven in buckleyi, taurinus, and verrucigerus, but smooth in leprieurii and pearsoni. The parasphenoids are large features with pointed, crest-like extensions and wings that tilt backward and outward. The base of the crest-like extensions has small tooth-like bumps in buckleyi, taurinus, and verrucigerus, while they are smooth in leprieurii and pearsoni. The prevomers are notably uniform and moderately developed. In each species, the front branch is located next to the premaxillary bone, and the side wings make up the front, inner, and back-inner edges of the internal nostrils. The tooth-bearing processes are typically large and angular and have many teeth. The sphenethmoid and otoccipitals are well formed; a dermal sphenethmoid is only found in taurinus.

Vertebral Column.—The cervical cotyles are consistently widely spaced. The neural arches are low and not overlapping. The transverse processes of the third presacral vertebrae are roughly the same width as the sacral diapophyses in all species, except for buckleyi, where the processes of the third presacral vertebra are slightly narrower than the diapophyses. Osteocephalus buckleyi is also recognized by having narrow transverse processes on presacrals five through eight (Fig. 7b); males have narrower processes than females. The processes are moderately wide but similar in width in pearsoni, taurinus, and verrucigerus, while they are almost identical in width to each other and to the sacral diapophyses in leprieurii (Fig. 7a). The sacral diapophyses of all species are moderately flared and inclined outward. The coccyx features a distinct dorsal ridge and has a bicondylar joint with the sacrum.

Pectoral Girdle.—The pectoral girdles are completely arciferal and have small, cartilaginous omosterna and moderately sized cartilaginous sterna. The coracoids are sturdy, and the clavicles are strongly curved. Procoracoid cartilage appears to be missing. The [Pg 18] scapulae are large, longer than the clavicles, and have a bicapitate structure at the proximal end. The suprascapulae are moderately sized and well ossified in leprieurii and taurinus. The suprascapula of verrucigerus is poorly ossified, and that of buckleyi is not ossified at all.

Pelvic Girdle.—The ilia of buckleyi, taurinus, and verrucigerus do not show any signs of a crest on the shaft, while leprieurii has a slight crest. The dorsal acetabular expansion of the ilia is moderately low in taurinus and verrucigerus, but significantly lower in buckleyi and leprieurii. All species have low dorsal bumps on their ilia. The ischia of leprieurii, taurinus, and verrucigerus are moderately expanded; however, buckleyi has a slightly less expanded ischium dorsally. The pubis of leprieurii, taurinus, and verrucigerus are ossified, while buckleyi has a cartilage-based pubis.

Throat Musculature and Vocal Sac Structure.—Tyler (1971) described the throat muscle structure of Osteocephalus. This genus features a moderately sized araphic submentalis muscle and a non-specialized intermandibularis with a long median aponeurosis. In buckleyi, the intermandibularis and submentalis muscles are completely separate, while in other species, there is a small connection between these muscles.

According to Tyler (pers. com.), Osteocephalus has three distinct types of vocal sac structures resulting from variations in the development of the interhyoideus muscle and the skin above it. In leprieurii and verrucigerus, the supramandibular sections of the interhyoideus create a simple tubular, posterolateral extension; there is no change in the related skin. Osteocephalus buckleyi and pearsoni show a greater development of the supramandibular portions of the interhyoideus, and the associated skin forms a wide, loose fold that extends from the ventromedial part of the throat to the base of the supratympanic fold. Like buckleyi and pearsoni, the supramandibular portion of the interhyoideus is significantly enlarged in taurinus. The vocal sac structure of taurinus is unique compared to other species in the genus, as the skin forms an everted pouch that hangs loosely beneath the supratympanic fold.

Justification of Synonymy.—Boulenger (1882:362) described 11 specimens of Hyla buckleyi. We have examined all of these and found that one (BMNH 1947.2.13.42) is actually O. leprieurii. Cochran and Goin (1970:213) limited the type locality to Canelos, Provincia Pastaza, Ecuador; we hereby choose BMNH 1947.2.13.44 from that locality as the lectotype. This specimen is a male with a snout-vent length of 37.9 mm; the diameter of the tympanum [Pg 20] is 3.5 mm, which is 81.4 percent of the eye's diameter. The type series, excluding BMNH 1947.2.13.42 (= O. leprieurii), consists of six males with snout-vent lengths ranging from 37.9 to 44.6 mm (mean 40.4 mm), and four females with snout-vent lengths between 50.0 and 53.9 mm (mean 51.5 mm). The males have a dorsum with a mixture of large and small tubercles, while the females have a nearly smooth dorsum. The skin on the sides, especially around the armpits, is areolate. The coloration features a creamy tan ground with irregular reddish-brown markings on the back and broad transverse bars on the limbs. The dorsal markings are narrowly bordered by creamy white; those on the back include an interorbital bar and a pair of longitudinal marks that start in the shoulder area and typically diverge towards the sacral region or converge into a broad median blotch. One specimen has a creamy white stripe running down the middle of its back from the tip of the snout to the vent. All types display large dark brown spots on the sides and the back of the thighs. The underside is pale creamy tan, with or without diffuse brown spots on the throat and chest.

The holotype of Hyla festae is a female with a snout-vent length of 75.0 mm; the tympanum has a diameter of 3.9 mm, which is 57.4 percent of the eye's diameter. The skin on the back is smooth, while the front part of the flanks is areolate. The back is a pale brown color with a large dark brown blotch running down the center and wide transverse bars, edged in cream, on the limbs. There are dark brown spots on the flanks, and the back sides of the thighs are dark brown. The throat and belly are grayish white with irregular dark brown spots.

The holotype of Hyla carri is a female with a snout-vent length of 66.1 mm; the diameter of the tympanum is 4.7 mm, which is 81.0 percent of the diameter of the eye. The skin on the back is smooth with small scattered bumps and has a network pattern on the front part of the sides. The back is tan with irregular dark brown spots on it and crossbars on the limbs; all the markings on the back are narrowly outlined in creamy white. Dark brown spots appear on the sides; the belly and the back surfaces of the thighs are tan without any dark spots.

The holotype of Hyla cabrerai is a female with a snout-vent length of 52.7 mm; the tympanum measures 4.0 mm, which is 76.9 percent of the eye's diameter. The skin on the back is slightly bumpy, and the front part of the flanks has a textured appearance. The back is a creamy tan color with dark brown patterns (including an interorbital bar, reticulations on the back of the head, three longitudinal streaks along the back, [Pg 21] and wide transverse bars on the limbs). There are irregular dark brown spots on the flanks. The underside is a pinkish tan with small reddish-brown spots on the throat and darker brown spots on the chest and belly.

In their description of Hyla cabrerai, Cochran and Goin (1970:217) mentioned: "This species, along with buckleyi and pearsoni, definitely form a tightly connected group. Both buckleyi and cabrerai have long hind legs, with the extended heel reaching the tip of the snout, while in pearsoni, the extended heel only reaches the eye. H. buckleyi has a dusky belly, while cabrerai has heavy spotting and pearsoni has a reticulated pattern. H. cabrerai appears to have the largest hands with the most webbing between the fingers; the other two species have less webbing between their fingers." The description of Hyla cabrerai was based on three specimens. We examined the holotype and one paratype (WCAB 13284 from Territorio do Amapá, Brasil). Another paratype from C. J. Goin's private collection, collected at Caño Tuí, between Mitú and Raudal de Yurupari, Comisaria de Vaupés, Colombia, was not examined.

Cochran and Goin (1970:211) based their description of Hyla carri on one pregnant female and said: "A large Hyla with vomerine teeth arranged in two U-shaped patches between the somewhat squarish choanae; reduced webbing between the fingers; and a pattern of dark dorsal blotches edged with light margins. This species is not similar to any other species known in Colombia. It is possibly most closely related to Hyla claresignata from Brazil, from which it can be distinguished by its more heavily spotted back, larger tympanum, and absence of dark anal spots."

Except for the inclusion of the name in checklists, Hyla festae hasn’t been mentioned in the literature since the original description.

The widespread renaming of species, which, based on their published diagnoses, appears to relate to clearly different species, is achievable by applying consistent criteria to the types and series of other specimens. In terms of measurements and proportions, the type specimens of the named taxa all fall within the variation range seen in a group of 18 males and 15 females from Provincia Pastaza, Ecuador, except for the ratio of the diameter of the tympanum to that of the eye in the female holotype of Hyla festae. In that specimen, the ratio is 0.574, while in the 15 females from Provincia Pastaza, the ratio is 0.587-0.905 (mean 0.736).

Ventral coloration is the most variable feature among the types. The underside of Hyla festae is vividly spotted; it is distinctly spotted in cabrerai, uniform tan in carri, and tan, flecked, or spotted in the type series of buckleyi. The ventral coloration in specimens from Amazonian Ecuador includes all variations seen in the types, except for festae, which has more ventral spots than any other individual.

The webbing on the hand usually excludes the second-to-last segments of the fingers, but in some specimens from Amazonian Ecuador, the webbing includes the base of the second-to-last segments of the fingers. In a few of these specimens, including the holotype of festae and one paratype of cabrerai, the webbing extends to the middle of the second-to-last segments of the third and fourth fingers. In the holotype of cabrerai, the webbing reaches the middle of the second-to-last segments of the third and fourth fingers and the base of the pad of the second finger.

The types of nominal taxa and specimen series from Guyana and Amazonian Ecuador show clear variation in dorsal coloration. The different dorsal patterns across all types are part of the variation seen in other specimens. Every specimen has some dark spots on the flanks, and all feature vertically barred lips, usually with a pale spot just below the eye. One of the most noticeable physical traits shared by all specimens is the texture of the skin on the front part of the flank. The skin is raised within a bumpy network of depressions. This bumpy skin condition is consistent across all specimens and isn't found in other species of Osteocephalus. The level of bumps on the skin of the back varies and shows sexual dimorphism. All males are bumpy, while smaller females are smooth or have only a few scattered bumps. Larger females typically have prominent bumps on the eyelids and the supratympanic fold.

In their description of Hyla carri, Cochran and Goin (1970:211) misrepresented the shape of the dentigerous processes of the prevomers, which are angular, not ʌ-shaped. Their claim that the Colombian Hyla carri is related to Hyla claresignata from southeastern Brasil is baseless. The latter species is smaller (40 mm), has a yellow back and belly, dark brown spots on the sides, slanted dentigerous processes of the prevomers, a small tympanum, and smooth skin on its back.

The underside color of Hyla festae is similar to that of Osteocephalus verrucigerus, but festae is different from verrucigerus because it has bumpy skin on its sides and clear dark patterns on its back. In verrucigerus, the skin on the sides is smooth, [Pg 23] and the back is a solid dark brown, except for a tan snout in females.

Comparing the types of the nominal species with collections of specimens from Guyana, Colombia, Ecuador, and Peru strongly indicates that the types represent a single taxon, the oldest name for which is Hyla buckleyi Boulenger, 1882. Therefore, we classify Hyla festae Peracca, 1904, Hyla carri Cochran and Goin, 1970, and Hyla cabrerai Cochran and Goin, 1970, as junior synonyms of Hyla buckleyi Boulenger, 1882.

Diagnosis.—1) Size is moderate, with noticeable differences between males and females; the maximum observed snout-vent length in males is 48.1 mm, while in females it’s 75.1 mm; 2) the skin on the back of males has a mix of large and small smooth tubercles; 3) the skin on the sides, especially at the front, has a bumpy texture; 4) webbing usually extends only to the base of the antepenultimate phalanx on the inner edge of the third finger; 5) the back is a pale tan or green with irregular, dark brown blotches, usually narrowly outlined in cream; 6) the belly is cream or tan, often tinged with brown or marked with brown spots in some individuals; 7) the lips have vertical brown and cream stripes; 8) the sides are creamy tan with irregular brown spots and/or diagonal marks; 9) the dermal roofing bones of the skull do not have exostosis; 10) there is no dermal sphenethmoid; 11) the nasal bones are widely separated in the middle; 12) the anteromedial edge of the frontoparietal bone is at the mid-level of the eye socket; 13) the frontoparietal fontanelle is partially exposed; 14) the palatine bone has a serrated edge; 15) the parasphenoid bone has tooth-like projections; 16) the zygomatic ramus of the squamosal extends about halfway to the maxillary arch; 17) the transverse processes of the third presacral vertebra are narrower than the sacral diapophyses; the transverse processes of presacral vertebrae 3-8 are similar in width and narrower in males than in females; 18) the intermandibularis and submentalis muscles operate independently; 19) the supramandibular part of the interhyoideus is well developed, with the associated skin forming a broad loose fold.

Osteocephalus buckleyi can be easily identified from all other species in the genus by its areolate skin on the front sides and its strikingly contrasting dorsal pattern. Additionally, females are unique because they have bumps on their eyelids and folds above their eardrums.

Distribution.—The outskirts of the Amazon Basin, in the Guianas and Amapá region in northeastern Brazil; the upper Amazon Basin from southern Colombia to east-central Bolivia; one location (Acevedo) in the upper Río Magdalena drainage in Colombia (Fig. 8). All locations are at elevations below 700 m. Records from Pallatanga and Santiago in Chimborazo Province, Ecuador (high up on the Pacific slopes of the Andes), are thought to be incorrect. 78 specimens from 40 locations.

Remarks.—In life, the back is green with dark markings. A male (KU 123171) from Santa Cecilia, Ecuador, was described as: "Back green with dark brown splotches. The front and back surfaces of the thighs are a dull blue. The underside is brown, speckled with white. The iris is greenish bronze with brown horizontal triangles and a central brown line." (W. E. Duellman, field notes, 16 June 1968.) A female (KU 126646) from Lago Agrio, Ecuador, was described as: "Back pale green with darker green splotches and a creamy yellow stripe down the middle. Side splotches are bronze-tan. The sides are tan with black splotches. The front surfaces of the thighs are dark brown. The back and underside of the thighs and shins are tan with dark brown splotches. The webbing is brown. There’s a green spot below the eye. A black bar behind the eye. The belly looks grayish brown—tips of the granules are white; the spaces between the granules are brown. The iris is golden bronze with black flecks around the edges and a central, horizontal reddish brown streak." (W. E. Duellman, field notes, 12 May 1969.)

No changes in coloration during development have been observed.

Justification of Synonymy.—The holotype of Hyla leprieurii is a female measuring 46.6 mm from snout to vent. The tympanum diameter is 3.7 mm, which is 69.8 percent of the eye diameter. The bones on the back are smooth, and the skin on the back is also smooth. The penultimate phalanges of the fingers are not part of the webbing. When we looked at the specimen on July 2, 1969, it was slightly soft and faded to a unique grayish-green color with faint darker bars across 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 back edge of the eye socket to the corner of the mouth, passing through the tympanum. All of the dorsal areas are grayish-white with broad transverse brown bands that are wider and less regularly shaped on the back compared to the limbs. There is one of these on the back of the head that is triangular. The underside is all white." (Free translation from French.)

The holotype of Hyla leprieurii britti is a male with a snout-vent length of 48.1 mm. The tympanum measures 3.6 mm in diameter, which is 65.5 percent of the eye's diameter. The skin on the back is tubercular; the tubercles are small on the head and the dorsal surfaces of the limbs, and slightly larger on the back. The penultimate phalanges of the fingers are not part of the webbing. Melin (1941:43) stated: "Above blackish brown with a very indistinct band between the eyes; iris with mottling of metallic sheen; the back parts of the upper jaw are whitish; sides of the body are mottled with blackish brown; hind limbs (especially the tibiae and tarsi) have narrow, diffuse crossbars; underneath, it is whitish with slight brown mottling along the jaw." We examined the type on 17 February 1969; at that time, it was dull brown on top with faint, narrow, dark brown transverse bars on [Pg 26] the back and dorsal surfaces of the limbs. A cream subocular spot was noticeable, and the underside was creamy white.

Melin (1941:42) stated that the holotype of Hyla leprieurii britti "resembles H. leprieurii Dum. & Bibr a lot. However, it differs from the latter species by its very concave loreal region, small tympanum, and almost uniformly brownish color, so it may at least be a subspecies of leprieurii." The pattern of narrow transverse bars on the backs of the holotypes of H. leprieurii and H. britti is a feature shared only by these two nominal taxa that are classified in Osteocephalus. Melin noted that britti differed from leprieurii in the depth of the loreal concavity and the size of the tympanum. Neither of these differences is significant when compared to a series of specimens. The depth of the loreal concavity is a highly subjective trait, and we observe no differences between the types. The ratio of the tympanum diameter to the eye diameter is relatively smaller in both holotypes (0.698 in leprieurii—♀; 0.655 in britti—♂) than in a 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 ratios in the types may result from geographic variation or shrinkage after many years in preservative (130+ years for leprieurii; 45 for britti).

Comparing the holotypes with groups of specimens from Ecuador, Guyana, and Surinam shows that one morphological species exists throughout the upper Amazon Basin and the Guianas, and that both type specimens belong to the same species. Therefore, 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 discussion 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 the same species. Another specimen (CNHM 69716) has been directly compared with the types of planiceps and vilarsi, and these are also considered to be the same species." With this reasoning, Cochran and Goin (1970:322) included Osteocephalus planiceps Cope, 1874, and Hyla vilarsi Melin, 1941, in the synonymy of Osteocephalus leprieurii.

We don’t agree with Cochran and Goin's classification and argue that planiceps and vilarsi are actually synonyms of Osteocephalus taurinus; we explain our reasons in the description of that species. We have looked at the specimens listed as O. leprieurii by Cochran and [Pg 27] Goin; several of them, including CNHM (= FMNH) 69716, are taurinus. Therefore, because Cochran and Goin confused two different taxa, their comparisons of certain specimens with types don’t hold much significance.

Cochran and Goin didn’t include Hyla leprieurii britti in their synonymy of Osteocephalus leprieurii, but they did discuss the name in their account of Osteocephalus orcesi (= O. verrucigerusHyla britti on hand, but when we directly compared it with the type of britti, the two turned out to be different. After examining the type of orcesi (SUNHM 13150), we have no doubt that the specimens we have are orcesi and that britti is a different, likely valid species."

Diagnosis.—1) Size is moderate, with clear differences between males and females; the largest male measured 48.4 mm from snout to vent, while the largest female was 61.5 mm; 2) Males have lots of tiny, pointy bumps on their back skin; 3) The skin on the sides is smooth; 4) The webbing extends to the base of the antepenultimate phalanx on the inner side of the third finger; 5) The back is tan or olive-brown with horizontal brown or olive stripes; 6) The belly is creamy white or light tan without any markings; 7) The lips have a creamy tan stripe and a spot under the eye; 8) The sides are light tan with no markings; 9) The bones on the top of the skull lack growths; 10) There is no dermal sphenethmoid; 11) The nostrils are positioned closely together; 12) The frontoparietal bone's front margin is located between the middle and the front of the eye socket; 13) The frontoparietal fontanelle is partially visible; 14) The palate is not serrated; 15) The parasphenoid does not have odontoids; 16) The zygomatic branch of the squamosal bone extends about halfway to the maxillary arch; 17) The transverse processes of the presacral vertebrae from 3 to 8 are roughly the same width as each other and the sacral diapophyses; 18) The intermandibularis and submentalis muscles are connected; 19) The supramandibular part of the interhyoideus forms a simple tubular extension towards the back and side, with the skin around it unchanged.

Osteocephalus leprieurii stands out from all other members of its genus because it has dark, transverse bars on its back. Two other hylids, Hyla lanciformis and multifasciata, found in the Amazon Basin, also have dark, transverse markings on their backs. However, both of these species differ from leprieurii as they possess pointed snouts, significantly longer hind limbs, and smooth skin on their backs.

Distribution.—The edges of the Amazon Basin, in the Guianas and the upper region in southern Colombia, Ecuador, Peru, and extreme western Brazil (Fig. 9). Most locations are at elevations of less than 500 m, but the species can be found on the lower Andean slopes up to elevations of 1100 m. 265 specimens from 31 localities.

Remarks.—Most adult leprieurii have distinct horizontal markings on their backs; these vary in width, extent, and arrangement. In some examples, like USNM 166557, some of the horizontal bars are broken into spots; in a few specimens, the back pattern consists only of small dark spots arranged in horizontal rows. These specimens have a back pattern similar to that of some taurinus. The horizontal nature of the back markings is further altered in some specimens, such as USNM 166555, where the dark bars are fragmented and slanted.

Extreme changes in color pattern occur in this species (Fig. 10). Juveniles with snout-vent lengths of less than 28 mm have an olive-brown back with a light cream stripe across the head and broad, cream-colored stripes along the sides; there are no dark transverse bars on the body and limbs. Individuals with snout-vent lengths of 30-35 mm have dark brown transverse bars on the back and limbs but still keep the light stripes along the sides, while the stripes disappear in larger individuals.

Coloration in life of specimens from Lago Agrio, Ecuador: "Males have dorsal colors that range from dark brown to ochre-tan, with consistent dark brown dorsal markings. Most specimens show dark brown and cream anal stripes, and the labial area is cream-colored. The flanks can be tan to white. The ventral color ranges from salmon to tan to white. The iris is bronze with a greenish tint and black patterns. In females, the dorsal coloration is the same as in males, but dark marks usually have cream outlines; the venter is tannish salmon." (W. E. Duellman, field notes, 12 May 1969).

Justification of Synonymy.—Goin (1961:13) suggested that Hyla pearsoni Gaige was an Osteocephalus, but Cochran and Goin (1970:217) [Pg 30] considered pearsoni to be a Hyla. The presence of exostosed dermal roofing bones, angular prevomerine dentigerous processes, and the structure of the vocal sacs are characteristics that place the species in Osteocephalus.

Diagnosis.—1) Size is moderate, with clear differences between sexes; the maximum snout-vent length observed in males is 46.2 mm, and in females, it's 54.7 mm; 2) The skin on the back of males has a few small, scattered non-spinous tubercles; 3) The skin on the sides is smooth; 4) The webbing extends to the base of the antepenultimate phalange on the inner edge of the third finger; 5) The back is tan with irregular brown blotches; 6) The underside is cream with fine brown reticulations; 7) The lips are dark with a pale vertical stripe below the eye; 8) The sides are pale tan with round, brown spots; 9) The dermal roofing bones of the skull are slightly protruded; 10) The dermal sphenethmoid is absent; 11) The nasal bones are narrowly separated in the middle; 12) The anteromedial margin of the frontoparietal bone is positioned between the mid and anterior levels of the eye socket; 13) The frontoparietal fontanelle is covered; 14) The palatine bone is not serrated; 15) The parasphenoid lacks odontoids; 16) The zygomatic ramus of the squamosal bone extends about halfway to the maxillary arch; 17) The transverse processes of the third presacral vertebra are about the same width as the sacral diapophyses; the transverse processes of presacral vertebrae 3-8 are similar in width; 18) The intermandibularis and submentalis muscles are connected; 19) The supramandibular part of the interhyoideus is well-developed, forming a broad loose fold of skin.

Osteocephalus pearsoni is easiest to identify compared to other members of its genus by its brown net-like pattern on the underside, round brown spots on the sides, and smooth skin on the sides. It is also the species with the least bumps in the genus.

Distribution.—Upper Amazon Basin and the Amazonian slopes of the Andes in central Peru (5,300 feet in the Río Ucayali drainage) and northern Bolivia (less than 1,640 feet in the Río Beni drainage) (Fig. 8). 6 specimens from 3 localities.

Remarks.—The specimen from Yaupi, Peru (KU 136312) is a subadult female with a snout-vent length of 39.8 mm. In life, the coloration was: "Dorsum light pinkish brown with a large rich chocolate brown blotch extending from the eyes to the front tips of the ilia; numerous small chocolate blotches on the flanks; dorsal surfaces of the thighs and shanks, canthus, and supraorbital region to the insertion of the forearm chocolate brown; supralabial border and a short bar from eye to lip bronze-white; venter bronze-white with many tiny chocolate brown flecks [which tend to form reticulations on the throat and chest]; anterior and posterior surfaces of thighs light olive-brown; iris mostly black with gold flecks." (Thomas H. Fritts, field notes, 23 [Pg 31] March 1970.) Based on this one subadult, it appears that reticulations on the venter develop with age.

Justification of Synonymy.—The holotype of Osteocephalus taurinus is a female with a snout-vent length of 103.9 mm. The tympanum measures 6.8 mm in diameter, which is 77.3 percent of the eye's diameter. The skull is heavily exostosed, and the lateral edges of the frontoparietals are raised to form distinct ridges. The skin on the back is smooth. When we examined the type on August 5, 1969, the specimen was soft and 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 back of the entire body, including the fore and hind limbs, is a light yellow-brown color that becomes lighter towards the belly. The belly is whitish, as are the undersides of the arms and legs. The throat is faintly marbled with brown. Roundish dark brown spots are randomly scattered in large numbers along the side of the body up to the eye; the tympanum is mostly surrounded by brown. A few distinct spots, which are usually elongated, can also be found on the sides of the body and on the back's posterior part. The dorsal surfaces of the fore and hind feet have somewhat obliquely arranged brown transverse bands, which are more intensely colored near the edges than in the middle of the band." (free translation from German.)

The holotype of Osteocephalus flavolineatus is a female with a snout-vent length of 81.8 mm. The tympanum diameter is 6.0 mm, which is 71.4 percent of the eye's diameter. The skull is heavily exostosed, and the lateral edges of the frontoparietals are raised to form a ridge on each side. The skin on the back is only slightly tuberculate. We examined the type on August 9, 1969, and found it to be in excellent condition. The color pattern is unchanged from what Steindachner described in 1862. The back is tan with irregular brown blotches, spots on the sides, and cross bars on the limbs. A narrow creamy white stripe runs down the middle of the back from the snout to the vent. The area under the eyes is creamy tan, and the belly is tan. Boulenger (1882) questionably grouped flavolineatus with taurinus. We've noticed that about 10 percent of taurinus specimens and some buckleyi specimens have a cream stripe down the middle of their backs. This is a common color variation in many Eleutherodactylus species. Without distinct physical traits, we can only conclude that the middle stripe is a variant in pattern, and Boulenger was right to link flavolineatus with taurinus.

The holotype of Osteocephalus planiceps is a male with a snout-vent length of 58.5 mm. The tympanum diameter is 4.9 mm, which is 77.8 percent of the eye's diameter. The skull has moderate exostosis, and the lateral edges of the frontoparietals are noticeably elevated. The skin on the back is tuberculated. 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 eye to the corner of the mouth; dermal scapular fold pale edged. Femur and tibia with dark crossbands on the exposed surfaces." We examined the holotype on September 25, 1969, and found it to be soft and worn. The coloration remains largely the same as described by Cope, who did not provide any way to differentiate planiceps from taurinus. The coloration and the morphometric and structural features of the planiceps type all fall within the range of variation shown by series of O. taurinus from the upper Amazon Basin.

The type of Hyla vilarsi is a pregnant female measuring 62.7 mm from snout to vent. The tympanum has a diameter of 4.8 mm, which is 73.8 percent of the eye's diameter. The dorsal bones of the skull are moderately protruding, and the lateral edges of the frontoparietals are noticeably raised. The skin on the back is smooth. [Pg 33] Melin (1941:42) described the coloration of the holotype as follows: "Above, a uniform reddish-brown; upper eyelids and sides of the head are a darkish brown; beneath the rostral edge is a narrow dark band, continuing as a broader light-edged one through the eye and tympanum towards the base of the forelimb and then further on as a line of black spots along the sides; the upper jaw is whitish with hints of dark cross bars (one clear underneath the eye); the sides of the body are darkish with black spots and marbling, often on a whitish background; thighs, tibiae, and tarsi each have two broad light-edged dark cross bars on a brownish background (less distinct on thighs); the sides of the thighs are finely mottled with brown; underneath is whitish with small, sparse spots along the jaw, on the chest, and on the sides." We examined the type on 17 February 1969, at which point the specimen was somewhat dried out, especially the hands and feet. The coloration appears largely the same as described by Melin, though he did not mention the presence of four elongated spots on the back.

The names Osteocephalus planiceps Cope and Hyla vilarsi Melin were incorrectly categorized by Cochran and Goin (1970:322), who put them under the synonym of O. leprieurii. Bokermann (1966:64) also grouped Hyla vilarsi with Osteocephalus taurinus without any explanation. The type specimens of both planiceps and vilarsi show moderately raised dermal roofing bones and clear cranial ridges. The type of planiceps has relatively large bumps on its back, while the type of vilarsi has spots on the throat, chest, and sides, along with stripes on its back. All these traits are typical of taurinus and not of leprieurii, which lacks raised features and cranial ridges and has stripes on the back, no spots on the throat, chest, and sides, and features small dorsal bumps in males.

The type of Hyla depressa is a male with a snout-vent length of 69.8 mm. The tympanum has a diameter of 5.2 mm, which is 77.6 percent of the diameter of the eye. The dorsal bones of the skull are moderately bumpy, and the sides of the frontoparietal bones are raised. The skin on the back is bumpy. The back is dull brown with a wide darker brown stripe running longitudinally, featuring indistinct edges from the snout to the area behind the sacrum. A narrow cream line runs along the middle of the back from the snout to the vent. The side of the head is dark brown, fading to a lighter brown underneath the eye. The back of the thighs is dull brown; the sides are light brown, and the underside is a pale creamy tan. Dark brown crossbars are present on the limbs. When we checked the type on January 3, 1969, it was in excellent condition. [Pg 34] Andersson (1945:75) compared the type of Hyla depressa with leprieurii and buckleyi, but he did not compare his specimen with taurinus, from which it shows no distinguishing features.

Osteocephalus taurinus is a widely spread and varied species, and it has been given several specific names. We believe that Osteocephalus taurinus Steindachner, 1862, is the oldest valid name for this large species found in the Amazon. The following names are junior synonyms: Osteocephalus flavolineatus Steindachner, 1862; Osteocephalus planiceps Cope, 1874; Hyla (Trachycephalus) vilarsi Melin, 1941; Hyla depressa Andersson, 1945.

Diagnosis.—1) Large size; clear sexual dimorphism; maximum recorded snout-vent length of 84.6 mm in males, and 104 mm in females; 2) skin on the back of males featuring many moderately large, spiny tubercles; 3) skin on the sides smooth; 4) webbing extends to the middle of the antepenultimate phalanx on the inner edge of the third finger; 5) back usually brown with a large dark brown blotch in the middle or, less often, several dark spots; some individuals have a narrow yellow line down the middle of the back; 6) belly cream or tan, with or without small, irregular brown flecks; 7) lips brown with a vertical cream bar below the eye in some, expanding into a pale stripe on the lip in some females; 8) sides tan or cream with or without small, irregular brown spots; 9) skull dermal roofing bones exostosed, casqued, and fused in large adults; 10) dermal sphenethmoid present; 11) nasals situated next to each other in the middle; 12) anteromedial margin of frontoparietals at mid-level of the eye socket; 13) frontoparietal fontanelle covered; 14) palatine serrated; 15) parasphenoid with odontoids; 16) zygomatic ramus of squamosal typically connecting with maxillary arch; 17) transverse processes of the third presacral vertebra about the same width as sacral diapophyses; transverse processes of presacral vertebrae 3-8 generally equal in width; 18) intermandibularis and submentalis muscles connected; 19) supramandibular part of interhyoideus well-developed; associated skin forming an evaginated pouch.

The somewhat bumpy back (in males), large size, extensive webbing on the hand, and frontoparietal flanges in adults help to differentiate taurinus from other members of its genus.

Distribution.—The Amazon Basin, the upper Orinoco Basin, and the Guianas. Most locations are below 500 m, but the species can be found at lower elevations in the Amazonian slopes of the Andes, reaching about 1000 m (Fig. 11). Records from Caracas, Venezuela, and those from Provincia Carchi and Provincia Esmeraldas, Ecuador, are considered inaccurate. The latter specimens were part of a collection sold to the University of Illinois; the collection includes many common Amazonian species that are not found in the Pacific lowlands. 516 specimens from 151 localities.

Remarks.—This common species varies greatly in size and color. There are noticeable differences in snout-vent length when comparing groups from different areas. The smallest calling males (CAS-SU 12351-6 from Rio Tapirapé, Brasil) measure between 46.5-60.3 (average 53.3) mm, while the largest (FMNH 140254, KU 92243-6, WCAB 9997, 10001, 10003-4 from Igarapé Marmelo, Brasil) range from 71.5-84.6 (average 77.6) mm. The average snout-vent lengths of males from other locations are as follows: Río Pastaza drainage, Ecuador 73.8 mm, Surinam 67.7 mm, Río Ucayali drainage, Perú 57.6 mm, and Guyana 55.5 mm. Although the difference between the smallest and largest adults is quite significant, there are populations that fill this gap. Additionally, the geographic distribution of small versus large frogs presents a confusing pattern. We have considered the possibility of including more than one species in taurinus, but based on preserved specimens, we cannot find consistent differences that clearly distinguish two or more taxa.

The color and pattern of taurinus vary so much that no single description can cover samples from the entire species range. We haven't been able to find geographic trends in color patterns; rather, the variation within a single sample can include the diversity seen in most other samples. There are a couple of minor exceptions. Some individuals across the range have a narrow light stripe down the middle of their back, but striped specimens are most common in the upper Amazon Basin. It's unusual for the species to lack dorsal markings altogether, but this is most frequent in individuals from the Guianas. A few individuals, like KU 105230, have scattered white spots on their backs.

The coloration of four male specimens observed from Lago Agrio, Ecuador (KU 126652-5) was: "Dorsal ground color ranging from tan to dark brown with darker brown markings. The flanks were creamy tan to yellow with brown or black flecks or mottling. The belly was a uniform creamy yellow or yellow with brown spots or reticulations. The iris was greenish yellow with radiating black streaks and a median, horizontal reddish-brown streak." (W. E. Duellman, field notes, 12 May 1969.) A female from Santa Cecilia, Ecuador (KU 123173) displayed: "Dorsum mottled olive-green and tan. The flanks were tan with brown spots. The belly and throat were creamy white, becoming tan toward the rear. The edge of the upper jaw was olive-green." (W. E. Duellman, field notes, 16 June 1968.) Another female from Santa Cecilia (KU 123175) had: "A brown dorsal surface with cream-colored mottling. The transverse bars on the legs were darker brown with cream-colored edges. The margin of the upper lip was creamy yellow. The anterior and posterior surfaces of the thighs were tan. The flanks were white with brown spots. The belly was creamy white. The iris was greenish bronze with heavy radiating black reticulations." (W. E. Duellman, field notes, 22 July 1968.)

The tendency for females to have a labial stripe at the back and the lack of dorsal tubercles in females has led to the classification of many such specimens as O. leprieurii.

Ontogenetic color change is minimal in taurinus. Most juveniles (under 40 mm in snout-vent length) are easy to identify. Juveniles tend to have dorsal markings made up of several small spots. As they grow, these spots typically merge, creating a large central blotch, though some adults keep the juvenile pattern. Cochran and Goin (1970:251) mistakenly identified several juveniles from Colombia as Hyla palpebrogranulata Andersson.

[Pg 37]

Justification of Synonymy.—Trueb and Duellman (1970:605) talked about how the names are assigned in the synonymy of O. verrucigerus; only a short summary is provided here.

The existing specimen of Hyla verrucigera is a young male with a snout-to-vent length of 32.0 mm. The back is smooth except for small bumps on the eyelids; the skin is loose, and the body feels soft. The specimen has faded to a light brown, with vague dark spots on its back and noticeable stripes on its limbs.

The holotype of Hyla riopastazae is a pregnant female with a snout-vent length of 64.7 mm. The back is smooth. The main color on the back is light brown with faint brown crossbars on the legs. The throat, chest, and belly are cream-colored with brown spots and markings.

The holotype of Hyla orcesi is an adult male with a snout-vent length of 52.6 mm. The back is heavily bumpy. The back is dark brown with subtle transverse stripes on the forearms and feet; the underside is a creamy brown.

Trueb and Duellman (1970) provided definitive proof that the types of H. verrucigera, riopastazae, and orcesi represent a juvenile, an adult female, and an adult male, respectively, of one species, the earliest available name for which is Hyla verrucigera Werner, 1901.

Diagnosis.—1) Size is moderate, and there's clear sexual dimorphism; the largest recorded snout-vent length is 54.3 mm in males and 65.8 mm in females; 2) Males have large, keratinized tubercles on their back skin; 3) The skin on the sides is smooth; 4) The webbing extends to the base of the antepenultimate phalanx on the inner edge of the third finger; 5) The back is uniformly dark brown or black, with a tan snout in females; 6) The underside is creamy white, heavily spotted with black or dark brown, especially in females; 7) The lips have a pale tan stripe and a suborbital bar; 8) The sides are a dull reddish brown; 9) The dermal roofing bones of the skull do not show exostosis; 10) The dermal sphenethmoid is missing; 11) The nasal bones are widely separated in the middle; 12) The frontoparietal bones have their anteromedial margin at the front border of the orbit; 13) The frontoparietal fontanelle is covered; 14) The palatine bones have a serrated edge; 15) The parasphenoid has odontoids; 16) The zygomatic ramus of the squamosal extends about halfway to the maxillary arch; 17) The transverse processes of the third presacral vertebra are about the same width as the sacral diapophyses; the transverse processes of presacral vertebrae 3-8 are similar in width; 18) The intermandibularis and submentalis muscles are connected; 19) The supramandibular part of the interhyoideus forms a simple, tubular, posterolateral extension; the surrounding skin is unchanged.

Osteocephalus verrucigerus can be identified from other members of the genus by its consistently dark back, heavily patterned belly, and the large, spiky tubercles on the back in males.

Distribution.—Lower Amazonian slopes (500-1840 m) of the Andes and on the western edge of the Amazon Basin in Ecuador and Peru; one location (Acevedo) in the upper Río Magdalena drainage in Colombia (Fig. 9). 40 specimens from 13 locations.

Remarks.—In male individuals, the back is a dull olive-green; the groin, the front and back of the thighs, the inner surfaces of the limbs, and the upper arms are dark brown. The underside of the limbs is pinkish-tan; the rest of the underside is a pale creamy tan with reddish-brown spots. The suborbital spot is a pale greenish-tan, and the iris is a deep reddish-brown. In females, the back is a dull olive-brown; the front of the head is tan, and the suborbital spot is yellowish-tan. The groin and hidden surfaces of the limbs are dark reddish-brown. The underside of the limbs is brown; the throat and chest are creamy white, while the belly is reddish-tan, both displaying dark brown mottling.

Considerable growth changes occur in coloration. Young ones are light-colored on top with a dark middle dorsal spot and dark stripes across the limbs. The underside is white. The change mainly involves an increase in dark pigment, which gradually covers up the juvenile pattern.

Tadpoles of this species have moderately long tails with low fins, sturdy bodies, two rows of labial papillae with the middle part of the upper lip bare, and two upper and five lower rows of teeth. Trueb and Duellman (1970) described the eggs, tadpoles, mating call, and differences in the adults.

Among the 33 genera currently recognized in the family Hylidae, there are two main types of vocal sac structures (Duellman, 1970b), [Pg 39] specifically the subgular type and the lateral type. Only four hylid genera, all from the lowland Neotropics, are known to have paired lateral vocal sacs: Osteocephalus, Argenteohyla, Phrynohyas, and Trachycephalus. The geographic distributions and physical characteristics of these four genera indicate that they are more closely related to each other than to any other hylid genera.

Of the four genera, Osteocephalus is the most general in terms of structure, and, like Phrynohyas, it doesn’t have any specific habits. Osteocephalus and Argenteohyla are also set apart from Phrynohyas and Trachycephalus by their vocal sac structures. The vocal sacs of Osteocephalus and Argenteohyla are located at the back and stick out towards the sides of the jaw when they’re inflated, while those of Phrynohyas and Trachycephalus are positioned more to the sides and extend back behind the jaw angles when inflated.

Although Osteocephalus and Argenteohyla have similar vocal sac structures, they are clearly different. The single-species Argenteohyla is a fairly specialized, partially burrowing frog (Trueb, 1970b), known for its smooth skin, medium-sized digital discs, and a large inner metatarsal tubercle. The overall shape of the skull is somewhat similar to that of Osteocephalus; both skulls have a well-defined roof, are wider than they are long, and feature posterolaterally oriented parasphenoid alae. Argenteohyla has small, slightly curved prevomerine dentigerous processes, unlike the large, angular ones found in Osteocephalus. The skull of Argenteohyla shows special features, likely adaptations for its partially burrowing lifestyle, which further set it apart from Osteocephalus. Compared to Osteocephalus, the cranium of Argenteohyla is slightly depressed at the front, the roofing bones are extensively casqued, and the palatines are sturdy.

Osteologically, Osteocephalus is more similar to Phrynohyas than either of the other two genera, but Osteocephalus and Phrynohyas are clearly different based on their vocal sac structure. Like Osteocephalus, skulls of the Phrynohyas genus are wider than they are long, have extensive dermal roofing bones, and feature posterolaterally oriented parasphenoid alae. In contrast to Osteocephalus, the dentigerous processes of the prevomers are curved rather than angular in Phrynohyas. Additionally, Phrynohyas is uniquely distinguished from Osteocephalus, Argenteohyla, and Trachycephalus by having well-developed [Pg 40] parotoid glands that produce a thick, milky volatile secretion.

Trachycephalus is the easiest to identify among the four genera being discussed. This genus consists of large frogs that have heavily built and fused skulls (Trueb, 1970a). The bones in the skin cover have intricate and distinctive patterns. The medial ramus of the pterygoid does not connect with the otic capsule, and the wings of the parasphenoid are oriented to the sides instead of towards the back. There is a dermal sphenethmoid present, and the parasphenoid has tooth-like structures. The basic skull structure shares many features with both Osteocephalus and Phrynohyas. The clear changes in the dermal roofing bones, as well as in the palatal and suspensory parts, appear to be adaptations that help Trachycephalus thrive in its unique lifestyle. The vocal sac structure of Trachycephalus resembles that of Phrynohyas, which further sets it apart from Osteocephalus.

Morphologically, Osteocephalus appears to be diverse and generalized enough to be a modern descendant of an ancestral type that may have led to Phrynohyas, Trachycephalus, and Argenteohyla. The specialized vocal sac structure in Phrynohyas and Trachycephalus suggests that these two genera might be closely related and represent a single evolutionary line from an ancestral stock similar to Osteocephalus. Argenteohyla is quite different from Phrynohyas and Trachycephalus and seems to represent a separate evolutionary line from the ancestral stock.

All of our observations of members of this genus were made at four locations: 1) Santa Cecilia at an elevation of 340 meters on the Río Aguarico, a tributary of the Río Napo, 2) Lago Agrio, 330 meters, about 14 kilometers east of Santa Cecilia, 3) Puerto Libre, 570 meters, on the Río Aguarico just east of where it forms from the confluence of the Río Cofanes and Río Chingua, and 4) the south slope of the Cordillera del Dué, above the Río Coca, at 1150 meters. Osteocephalus leprieurii was found at all four locations, and buckleyi was found at all but the last; taurinus was found at Santa Cecilia and Lago Agrio, and verrucigerus was found only in the Cordillera del Dué. Our data is based on collections of 113 frogs and three lots of tadpoles, along with observations on calling sites and young. The observations are summarized by species, as follows:

[Pg 41] Osteocephalus buckleyi.—No breeding activity was noted. Males were only spotted at night in March, June, and July. One was sitting on a Heliconia leaf in a swamp at Puerto Libre, and two were on bushes in the forest at Santa Cecilia. A pregnant female was found on a recently cut tree at Lago Agrio on the night of May 12, 1969.

Osteocephalus leprieurii.—Males were heard calling sporadically at Puerto Libre in July 1968 and at Santa Cecilia in May 1969. A small group was found on the night of May 12, 1969, at Lago Agrio, where the frogs were sitting on branches of fallen trees over a temporary pool. The call is a soft rattling chuckle. In late April and May, many pregnant females and males with well-developed breeding features were collected from trees as they were cut down at Lago Agrio. The reproductive condition of the frogs suggests they likely breed in May. One individual called almost every night from a large tree at Puerto Libre between July 4-17, 1968. The tree was cut down on the latter date, but no frog was found. Two nights later, apparently the same individual called from a bromeliad at about 10 m high on a large bamboo next to the felled tree; the frog was collected when the bamboo was cut down.

Throughout the rainy months we worked in Ecuador (April-August), we occasionally spotted individuals sitting on bushes or low trees at night. We only observed large numbers of adults during a clearing operation that led to the felling of many large trees. Therefore, it seems likely that leprieurii lives in the treetops. A partially digested adult male was found in the stomach of a Hemiphractus proboscideus.

At Santa Cecilia, many recently transformed young frogs and juveniles were found in June and July 1968. Most of these were on low bushes or herbs in the swamp forest at night; some were found in unfolded Heliconia leaves during the day, and one was spotted on the forest floor in daylight. The snout-vent lengths of 18 specimens ranged from 12.3 to 17.0 mm, with an average of 15.1 mm. The smaller frogs had recently transformed, as indicated by the melanophore deposits above the vent. The coloration of the young frogs is noticeably different from that of the adults (see account of O. leprieurii), so the connection between young and adults wasn't made until individuals with intermediate patterns were collected at Lago Agrio in May 1969. It is likely that the juveniles found in June and July are the offspring of an April or May breeding. We have been unable to connect tadpoles with this species.

Osteocephalus taurinus.—A small group was observed at Lago Agrio [Pg 42] on May 12, 1969. Males were calling from the ground near a small pool among recently cut trees. The males were very cautious and, when approached, jumped onto branches and ran up the trunks; this behavior was noted by Bokermann (1964). The call consists of a series of low-pitched, short notes—similar to a slow trill—with four to six notes per call group. These call groups are repeated two, three, or four times, followed by a pause of several minutes. Although no mating pairs were found, several pregnant females were collected at Lago Agrio in May, so it can be assumed that the species breeds in May. From April through July, occasional individuals were seen on bushes and trees at night. During clearing operations at Lago Agrio, several individuals were collected from the tops of trees as they were being cut down.

Osteocephalus verrucigerus.—Observations were made in a wide, shallow ravine where there was a small stream. On August 2-4, 1968, males were seen calling from low bushes and rocks at the edge of a calm pool in the stream. The call consists of a series of well-pulsed, low-pitched guttural notes produced at a rate of 5-10 per minute. One mating pair was found at the base of a bush next to the pool on August 3. Another female was spotted on a branch of a tree 2 meters above the ground and 10 meters from the stream. Tadpoles of this species were found in the calm silt-bottomed pool.

The locations for each of the specimens examined are described in the following paragraphs. The data is organized as follows: alphabetically by country, state (department or province), and locality; alphabetically by the first letter in the abbreviations for the museums, and numerically after each museum abbreviation. Specimens without precise locality data are listed first in the smallest political unit possible; localities that cannot be found on maps or whose positions are not known to us are enclosed in quotation marks. If there is more than one specimen under a single museum number, the number of specimens is indicated in parentheses after the museum number. Unless stated otherwise, all specimens are preserved in alcohol.

BOLIVIA: El Beni: Ivón, BMNH 1967.2070-1. Santa Cruz: Buenavista, CM 4333, 4339, UMMZ 66563-5.

BRASIL: Amapá: No specific location, WCAB 13284.

COLOMBIA: Amazonas: Río Guacaya, USNM 152759. Huila: Acevedo, [Pg 43] Río Suaza, FMNH 69702. Nariño: Rumiyacu, FMNH 54756. Meta: Río Guejar, Campamento La Macarena, USNM 152199.

ECUADOR: No specific location, NHMW 6209, WCAB 35499. Chimborazo: Pallatanga, BMNH 1947.2.13.46; Santiago, FMNH 42529. Morona-Santiago: "Río Santiago" (= Río Zamora), MIZS 2950. Napo: Lago Agrio, KU 126646; Puerto Libre, Río Aguarico, KU 123172; Santa Cecilia, AUM 8138, KU 105208-9, 109506, 123171. Pastaza: Alpayacu, BMNH 1912.11.1.64; Canelos, BMNH 1947.2.13.40-1, 1947.2.13.43-5; Colonia Mena, Río Conambo, ZSM 33/1962; Don Tomás, USNM 166014; Guaché, Río Pastaza, AMNH 79986; Río Bobonaza, USNM 166005; Río Capahuari, USNM 166554; Río Conambo at Río Shiona-yacu, USNM 166018; Río Copataza, upper Río Pastaza, USNM 166007-13; Río Pastaza, NHRM 1946; Río Pucyacu, USNM 165997 (skeleton), 165998-6001; Río Rutuno, USNM 166006; Río Villano, USNM 166002-4; Sarayacu, BMNH 1947.2.13.36-9, MCZ 26090, ZMB 10166.

GUYANA: Mazaruni-Potaro: Kartabo, AMNH 70971; Membaru River, upper Mazaruni River, UMMZ 85168; Oko Mountains, FMNH 26722-3. North West: Amakura River, Haulover, UMMZ 83558-9. Rupununi: Marudi River, AMNH 46233; Shudi-kar-wau, AMNH 49252. West Demerara: Dunoon, UMMZ 52449, 52508.

PERU: Junín: Chanchamayo, BMNH 1911.12.13.79-80. Loreto: Andoas, AMNH 79984-5; Cashiboya, AMNH 43454; San Antonio, Río Itaya, AMNH 43218. Puno: Yahuaramayo, BMNH 1913.2.25.7.

SURINAM: Suriname: Powakka, CM 44217.

SOUTH AMERICA: No specific location, NHMW 6208.

BRASIL: Acre: Tarauacá, FMNH 83247. Amazonas: Rio Javarí, Benjamin Constant, CAS-SU 12620; Río Uaupés, north of Rio Japú, NHMG 489.

COLOMBIA: Amazonas: Gino-goje, lower Río Apoporis, MCZ 28038, 28040-2, 28044, USNM 152136-8.

ECUADOR: No specific location, WCAB 35452-3; "Napo-Pastaza," USNM 166571. Napo: Avila, UMMZ 92093; south slope Cordillera del Dué, KU 123170; Lago Agrio, KU 125961-2 (skeletons), 126611-44, UMMZ 129326 (2); Limón Cocha, Río Napo, KU 99210-6, UIMNH 63087-9, 63098, 63106-9, 63118-9, 64802-4, 64858, 87998-9, 88001-30, 88437-8, 88580, 88604-5, 89852-97, 89999-90000; Loreto, CAS-SU 11439, WCAB 36526; Puerto Libre, Río Aguarico, KU 123190-1; Puerto Napo, UIMNH 55818-20; Río Cotapino, UMMZ 92094; Río Napo, UMMZ 92078; Santa Cecilia, AUM 8099, 8102, 8113-5, 8127-9, 8131, 8137, 8139-46, 8148, KU 105210-20, 109509-11, 111971, 122964-87, 123169, 126645. Pastaza: Canelos, BMNH 1947.2.13.42, KU 120915; Río Alpayacu, UMMZ 92079; Río Arajuno, USNM 166560-2, WCAB 40176; Río Oglán, USNM 16655203, 166558; Río Rutuno, USNM 166559; Río Shilcayacu, below Puyo, USNM 166557; Río Villano, USNM 166551.

FRENCH GUIANA: No specific location, MNHN 4629. Inini: Lunier River, MNHN 98/217.

GUYANA: Mazaruni-Potaro: Kartabo, AMNH 70967-8, 70972, 70976. Rupununi: Shudi-kar-wau, AMNH 49255. West Demerara: Demerara Falls, BMNH 72.10.16.23, 72.10.16.37-8.

PERU: Loreto: Estirón, Río Ampiyacu, MZUSP 31033-4; Pebas, CAS-SU 3158, 3160; Roaboya, AMNH 43064.

[Pg 44] SURINAM: No specific location, MCZ 2036, RMNH 11468. Marowijne: Camp 3, RMNH 13045-6; Wane Creek North, RMNH 11469-70. Saramacca: Right Coppename River, RMNH 11467.

BOLIVIA: El Beni: upper Río Beni, downstream from the mouth of Río Mapiri, MCZ 15565, UMMZ 57548, 67464-5; Rurrenbaque, UMMZ 57533.

PERU: Pasco: Yaupi, KU 136312.

BOLIVIA: El Beni: Ivón, BMNH 1967.2040; Reyes, UMMZ 57532. La Paz: San Ernesto, Mapiri District, BMNH 1901.8.2.54. Santa Cruz: Buenavista, AMNH 33951-2, 33958, BMNH 1927.8.1.19, 1927.8.1.118, FMNH 27091, UMMZ 63319-21, 63959(2), 63961(2), 66566(2), 66567, 66568(2), 66569 (2), 66570, 66571(2), 66575-6, 68196; Río Mamore, 2 km N Boca Chaparé, AMNH 79324; Sara, CM 3840-1; Surutu, CM 3814-5.

BRASIL: No specific location: "Interior," BMNH 74.7.16.8-9. Acre: Plácido de Castro, MZUSP 6518; Tarauacá, WCAB 2496. Amazonas: Cucuí, NHMW 16495; Manacapurú, ZMB 28492, ZSM 278/1925; Manáus, MCZ 56281, NHMW 16492; Maués, AMNH 69623, 76177; Taracuá, NHMG 488, WCAB 18463-4. Mato Grosso: Mabuca, MZUSP 4272; Posto Coluene, Rio Xingú, WCAB 812; "Puerto Cabello," AMNH 3154; Tapirapé, AMNH 73647-62, CAS-SU 12351-6, MNHN 46/324. Pará: No specific location, MPEG 623-6; Belém, KU 129866; Cachimbo, FMNH 175876, UIMNH 42149, WCAB 813; Cametá, NHMW 15892; Gurupá, BMNH 96.6.29.13; Ilha de Marajó, BMNH 1923.11.9.20-4; Ilha Mexicana, ZSM 111/1911, 112/1912; "Ponto Dois Indios," BMNH 1939.1.5.5; Santarém, BMNH 75.10.22.1-4, MCZ 354. Rondonia: Abuná, CAS 49773-4, FMNH 64239; Forte Principe da Beira, WCAB 10230; Igarapé Marmelo, FMNH 140254, KU 84725 (skeleton), 92243-6, 92247-8 (skeletons), WCAB 9997, 10001, 10003-4; Porto Velho, MZUSP 16343.

COLOMBIA: Amazonas: Gino-goje, lower Río Apoporis, USNM 152139; Leticia, USNM 152010-1; Raudal de la Playa, lower Río Apoporis, MCZ 28050; Río Apoporis, MCZ 28060. Boyacá: Sutatenza, USNM 152054-6. Cundinamarca: Medina, MCZ 16269-71, USNM 152089-90, 152092-7, 152757. Meta: El Mico, Río Guejar, USNM 152203; Río Duda, Sierra de Macarena, AMNH 79914; Río Guapaya, Sierra de Macarena, FMNH 81332; Río Guaviari, Casa de Piedra, UTA No number. Putumayo: Río Mecaya, FMNH 69711-4, 69716. Vaupés: Gomogoje, lower Río Apoporis, MCZ 28048.

ECUADOR: No specific location, WCAB 35451, 35785; "Oriente," UMMZ 90418. Carchí: below Salinas, USNM 166059. Esmeraldas: Carondelet, UIMNH 53560-9; Lagartera, Río Caoni, UIMNH 53441, 53458-79. Morona-Santiago: Macuma, UIMNH 63142-3, 63145, 63147, 63151, 63154, 63157, USNM 166060. Napo: Avila, UMMZ 92077; Cuyabeno, UIMNH 63158, 90111; Lago Agrio, KU 126647-55; Limón Cocha, Río Napo, AUM 8132-4, KU 99207-8, 99421-3, 99424 (skeleton), 99425, UIMNH 64801, 87798, 87800, 88032-5, 88576, 90066, 90082, 90102, 90104, 90314, 90984; Loreto, WCAB 35352; Río Cotapino, UMMZ 92080; Río Napo, UMMZ 84120; San José Abajo, AMNH 1295, 1449, 22180, 79990; Santa Cecilia, AUM 8117, 8150, KU 105230-3; south slope Volcán Sumaco, USNM 166570. Pastaza: No specific location, ZSM 31/1956; Arajuno, USNM 165995; Bufeo, lower Río Bobonaza, USNM 166046-8; Canelos, BMNH 80.12.5.179, 1947.2.13.48, UMMZ 89066; [Pg 45] Don Tomás, Río Bobonaza, USNM 166049-50; Montalvo, CAS-SU 10320, USNM 165987-9, 166058, 166566; 2.5 km SE Puyo, USNM 166051; Río Arajuno, USNM 166043-5; Río Arajuno (headwaters), USNM 166053; Río Bobonaza, WCAB 3613-4, 35504; Río Capahuari, USNM 165990, 166555-6; Río Capahuari (headwaters), USNM 166057; Río Conambo, USNM 166569, ZSM 28/1962, 35/1962; Río Conambo at Río Ollaguanga, USNM 166568; Río Conambo at Río Shiona-yacu, USNM 166019, 166563-5; Río Corrientes, USNM 195994, 166020-38, WCAB 3841-2; Río Huiyo-yacu, Pico de Conambo, USNM 166052; Río Pastaza, MCZ 19697; Río Pastaza (drainage), NHRM 1966, USNM 165996; Río Pindo, USNM 166039-41; Río Pindo at Río Tigre (village), USNM 165992-3, 166042; Río Pucayacu, USNM 166054, 166056; Río Rutuno, USNM 166055; Río Solis, upper Río Bobonaza, WCAB 39914; Río Villano, USNM 165991, 166567; Sarayacu, BMNH 80.12.5.213, 80.12.5.239-40, MZUSP 323; Shell Mera, KU 99420. Zamora-Chinchipe: "Yani-Inzari," AMNH 43259, 43394; Zamora, AMNH 78928.

FRENCH GUIANA: Cayenne: Crique Grégoire, UP 40; Maripa, Oyapok River, UP 72; Oyapok River, UZM 1473. Inini: Crique Gabrielle, UP 118-20.

GUYANA: No specific location: RMNH 1873(3), ZMB 3102(2). East Demerara: Atkinson Field, ASU 11622. Mazaruni-Potaro: Chinapora River, upper Potaro River, BMNH 1905.11.1.20-1; Kamakusa, AMNH 21416, 21418-9, 21422; Kartabo, AMNH 11689, 11691, 11697-9, 11703, 11706-8, 23107, 39730, 70966, 70969-70, 70973-5, USNM 118057; Moraballi Creek, Essequibo River, BMNH 1930.10.10.47-51; Oko Mountains, FMNH 26692-705; upper Potaro River, Tung District, BMNH 1905.11.1.40; Rockstone, FMNH 26591. North West: Amakura River, Haulover, UMMZ 83735. Rupununi: north of Acaray River, west of New River, KU 69747-8; Kuyuwini Landing, AMNH 46283; Pakaraima Mountains, BMNH 1933.6.19.49; Shudi-kar-wau, AMNH 10665, 39637, 49256(2). West Demerara: Demerara, CAS 54773-4; Demerara Falls, BMNH 72.10.16.16-22, 72.10.16.25-32; Dunoon, MCZ 4834, UMMZ 46736, 52493-4, 52502, 52504-5, 57271; Vryheid, BMNH 78.12.13.18.

PERU: Amazonas: Río Cenepa, AMNH 43400. Huanuco: Monte Alegre, Río Pachitea, AMNH 43014, 43019. Loreto: Achinamisa, Río Huallaga, AMNH 42178, 42502; Andoas, Río Pastaza, AMNH 79991; Cashiboya, AMNH 43388, 43453; Estirón, Río Ampiyacu, CAS 93264-74, 93276, 93278-9, 93281, 93283-6, 93289, 93311, 93327; Igarapé Champuia, upper Río Curiuja, MZUSP 10339; Iquitos, AMNH 42204, 42442, 43468, NHMW 6118; Lago de Miraño, mouth of Río Napo, AMNH 42712, 43186; Nauta, ANSP 11399; Ollanta, AMNH 42865; Pampa Hermosa, Río Cushabatay, AMNH 43124, 43146; Pebas, CAS-SU 6375; Pucallpa, MJP 101(2), 140(3); Punga, Río Tapiche, AMNH 43194; "Rancho de Indiana, Iquitos District," MVZ 16890; upper Río Abujao, AMNH 42908; Río Itaya, AMNH 42755; upper Río Pisqui, AMNH 43536; Río Tapiche at Río Contaya, AMNH 42983; Río Utoquinia at Brazilian border, AMNH 43137; Sobral, Río Tamaya, AMNH 43242; Yurimaguas, BMNH 84.2.18.50. San Martín: Cainarachi, AMNH 42763; Moyobamba, ZSM 19/1914.

SURINAM: No specific location, BMNH 70.3.10.67, NHMW 18433.3. Brokopondo: Afobaka, RMNH 16536; Brownsweg, RMNH 16537; Railway km. 121, RMNH 16534. Marowijne: Djai Creek, RMNH 16513-4; Maroni River, ZMB 8240, 8531; Nassaugebergte, RMNH 16517-33; Paloemeu, USNM 159025; Swamp Camp, RMNH 16515. Nickerie: Sipaliwini, RMNH 16538. Saramacca: Left Coppename River, RMNH 16535; Tibiti, RMNH 16516. [Pg 46] Suriname: Berlijn, RMNH 15064; Powakka, CM 44226; Zanderij, CM 50568.

VENEZUELA: Amazonas: Cerro Duida, UPR-M 2875; Cerro Marahuaca, UPR-M 114-5; Esmeralda, AMNH 23174; Iniridi, SMF 2640; La Culebra, MCZ 28572, UPR-M 117; Laguna, between Tama Tama and Esmeralda, UPR-M 2760; Río Pescado, AMNH 23177; Tapara, UPR-M 113. Distrito Federal: Caracas, BMNH 51.7.17.182.

COLOMBIA: Huila: Acevedo, Río Suaza, FMNH 69709-10.

ECUADOR: No specific location, ZMB 16589. Napo: Avila, UMMZ 90413; south slope of Cordillera del Dué, KU 123176-88, 123189 (skeleton), 124208 (eggs), 124209-11 (tadpoles); L'Alegria, USNM 167472-3; Río Pacayacu, a tributary of Río Cotapino, CAS-SU 13150; southeast slope of Volcán Sumaco, CAS-SU 11442. Pastaza: Abitagua, CAS-SU 5067, FMNH 25791, 27619, UMMZ 90414, 92092; Alpayaca, Río Pastaza, BMNH 1912.11.1.64; Mera, UMMZ 90412(4). Tungurahua: Baños, NHRM 1960.

PERU: Ayacucho: La Mar, Sivia, Río Apurímac, FMNH 39853. Huánuco: Río Pachitea, halfway between Puerto Victoria and Puerto Inca, CAS-SU 17745. Junín: Satipo, MJP 38.

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