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Title: A Synopsis of Neotropical Hylid Frogs, Genus Osteocephalus Author: Linda Trueb William Edward Duellman Release date: October 3, 2011 [eBook #37602] Language: English Credits: Produced by Chris Curnow, Tom Cosmas, Joseph Cooper and the Online Distributed Proofreading Team at http://www.pgdp.net *** START OF THE PROJECT GUTENBERG EBOOK A SYNOPSIS OF NEOTROPICAL HYLID FROGS, GENUS OSTEOCEPHALUS *** Produced by Chris Curnow, Tom Cosmas, Joseph Cooper and the Online Distributed Proofreading Team at http://www.pgdp.net _OCCASIONAL PAPERS_ of the MUSEUM OF NATURAL HISTORY The University of Kansas Lawrence, Kansas --------------------------------------------------------------- NUMBER 1 APRIL 29, 1971 --------------------------------------------------------------- A SYNOPSIS OF NEOTROPICAL HYLID FROGS, GENUS _OSTEOCEPHALUS_ By LINDA TRUEB[1] AND WILLIAM E. DUELLMAN[2] [1] Research Associate, Division of Herpetology, Museum of Natural History, University of Kansas. [2] Curator, Division of Herpetology, Museum of Natural History, University of Kansas. When we initiated a study of the herpetofauna at Santa Cecilia in Amazonian Ecuador in 1966, we were immediately confronted with many kinds of animals that we could not identify with the existing literature. Comparisons of our specimens with those preserved in other museums resolved some of the problems, but many identifications could be made only after study of type specimens; even then some determinations remained questionable. We now find that in order to prepare a meaningful account of the herpetofauna of Santa Cecilia, we must complete several taxonomic studies, the limits of which extend far beyond eastern Ecuador. Because of our interests in hylids we have begun our studies on these frogs. One of us (Trueb, 1970a) studied the cranial osteology of casque-headed hylid frogs and redefined the genus Osteocephalus but did not determine the number of species in the genus. Our work in Amazonian Ecuador resulted in the discovery of the sympatric occurrence of three species at each of two localities; one of these species was found with a fourth species at another locality. Study of museum specimens confirmed the recognition of these four species in the Amazon Basin and lower Amazonian slopes of the Andes. A fifth species from Bolivia and Perú also is included in the genus. Examination of museum specimens has provided data on the geographic variation in, and distribution of, the five species. However, our conclusions pertaining to some populations need substantiation, because we have been hampered by inadequate material from areas beyond Ecuador. More than half of the 905 specimens of _Osteocephalus_ are from Ecuador, a relatively small part of the total range of the genus. In this paper we are presenting a taxonomic review of the genus _Osteocephalus_; of necessity our study has been at the alpha level. We have utilized all of the usual external characters, as well as osteological features in our definitions of the species. Tadpoles and mating calls are available for only one species, _O. verrucigerus_ (Trueb and Duellman, 1970); these and other important systematic characters, such as karyotypes, are not available for the group at this time. Our tendency has been to take a conservative view of species; thus it is doubtful that any subsequent worker will recognize fewer species in the genus. Our observations on these frogs in Amazonian Ecuador are presented in a final section of this paper. ACKNOWLEDGMENTS For the loan of specimens or for the provision of working space in their respective institutions, we are indebted 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. Study of specimens in European museums was made possible by a grant (No. 5063) from the Penrose Fund of the American Philosophical Society. Field work in Ecuador was partially supported by grants from the Watkins Fund of the Museum of Natural History, University of Kansas. At our base camp at Santa Cecilia, Ecuador, we enjoyed the hospitality of Ing. Ildefonso Muñoz B. Transportation in Ecuador was generously provided by the Texaco Petroleum Company. During the course of our field work Stephen R. Edwards and Thomas H. Fritts contributed directly to our study of _Osteocephalus_. Michael J. Tyler of the South Australian Museum provided information on the vocal sac structure. We extend our sincere thanks to all of these persons for their contributions to our endeavors. MATERIALS AND METHODS We have examined 893 preserved frogs, including the type specimens of all included nominal taxa, 8 skeletons, 1 lot of eggs, and 3 lots of tadpoles that we refer to the genus _Osteocephalus_; in addition skulls were removed from five preserved specimens, and radiographs were made of 12 other preserved specimens. We have been fortunate in seeing living individuals of all species, except _O. pearsoni_, but we have colored photographs of a living specimen of that species. Figures 1 and 2 were drawn from projected colored transparencies of living frogs. Terminology follows that of Duellman (1970b). On the distribution maps solid symbols indicate localities from which we have examined specimens; open symbols represent additional locality records based on the literature. Throughout the text specimens are listed by their catalogue numbers preceded by the appropriate museum abbreviation, as follows: AMNH American Museum of Natural History ANSP Academy of Natural Sciences of Philadelphia ASU Arizona State University AUM Auburn University Museum BMNH British Museum (Natural History) CAS California Academy of Sciences CAS-SU Stanford University Collection (In California Academy of Sciences) CM Carnegie Museum FMNH Field Museum of Natural History KU University of Kansas Museum of Natural History MCZ Museum of Comparative Zoology, Harvard University MIZS Museo ed Istituto di Zoologi Sistematico, Università di Torino MJP Museo Javier Prado, Lima MNHN Muséum National d'Histoire Naturelle, Paris MPEG Museu Paraense Emiliano Goeldi, Belém MVZ Museum of Vertebrate Zoology, University of California, Berkeley MZUSP Museu de Zoología, Universidade da São Paulo NHMG Naturhistoriska Museet Göteborg NHMW Naturhistorisches Museum, Wien NHRM Naturhistoriska Riksmuseet, Stockholm RMNH Rijksmuseum van Natuurlijke Histoire, Leiden SMF Senckenbergische Museum, Frankfurt UIMNH University of Illinois, Museum of Natural History UMMZ University of Michigan Museum of Zoology UP Université de Paris UPR-M University of Puerto Rico, Mayagüez UTA University of Texas, Arlington USNM United States National Museum UZM Universitets Zoologiske Museum, Copenhagen WCAB Werner C. A. Bokermann, São Paulo, Brasil ZMB Zoologisches Museum Berlin ZSM Zoologisches Sammlung München HISTORICAL RESUMÉ Because of the taxonomic confusion that has surrounded the generic name _Osteocephalus_ and two of the species (and their synonyms), we present a brief resumé 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 having a well-ossified skull and smooth dorsal skin. This specimen escaped from the covetous eyes of Johann Tschudi, who prematurely named several species on the basis of specimens in Paris, and survived without an epithet until Duméril and Bibron (1841) proposed for it the name _Hyla leprieurii_. The description of the species is fairly detailed, but the specimen was not illustrated. This is the earliest trivial name now associated with _Osteocephalus_. Fitzinger (1843) in his generic synopsis of amphibians and reptiles proposed the generic name _Osteocephalus_ but did not associate a specific name with the genus. Consequently, _Osteocephalus_ Fitzinger, 1843, is a _nomen nudum_. Franz Steindachner followed Leopoldo Fitzinger at the Naturhistorisches Museum in Vienna, where he had access to Fitzinger's notes and, of course, the important collections housed in that museum. Steindachner (1862) named two species of _Osteocephalus_ on the basis of Brasilian specimens collected by Johann Natterer. Both species were named in the same publication; _O. taurinus_ appeared on page 77, and _O. favolineatus_, on p. 80. This is the earliest association of the generic name _Osteocephalus_ with a specific name and a description, both of which satisfy the Code of Zoological Nomenclature for generic availability. Therefore, Steindachner is the authority for the generic name _Osteocephalus_, which has _O. taurinus_ as the type species by original designation. It is not possible to determine whether or not Steindachner's usage of _Osteocephalus_ was the same as that intended by Fitzinger 19 years earlier. Steindachner (1862) gave reasonably good descriptions of his two new species and provided excellent illustrations of the two specimens, both large females. Apparently impressed by the similarities between _Trachycephalus nigromaculatus_ Tschudi, 1838, and _Osteocephalus taurinus_, Steindachner (1867) used the combination _Trachycephalus (Osteocephalus) taurinus_. This ambiguous usage for the 1860's precludes our determining if Steindachner was in effect synonymizing _Osteocephalus_ with _Trachycephalus_ or whether he was placing _Osteocephalus_ in a subgeneric status. Steindachner (1867) did not mention _O. flavolineatus_; perhaps by that time he had concluded that _flavolineatus_ was only a color morph of _taurinus_. Cope (1867) placed _Hyla leprieurii_ in the genus _Hypsiboas_ Wagler, 1830. Cope (1874) named _Osteocephalus planiceps_ from Nauta, Perú. The single specimen was among the collections made by the Orton Expedition to the upper Amazon Basin and was deposited in the Academy of Natural Sciences in Philadelphia. Boulenger (1882) placed both _Osteocephalus_ and _Trachycephalus_ the synonymy of _Hyla_; he recognized _Hyla taurina_ (with _O. flavolineatus_ as a synonym), _H. leprieurii_, and _H. planiceps_. In the same publication Boulenger named _Hyla buckleyi_ on the basis of 10 specimens in the British Museum from Ecuador; in the description he stated that _buckleyi_ was like _leprieurii_ and _taurinus_ in having paired lateral vocal sacs. Boulenger held a lasting influence on taxonomic herpetology, and his generic synonymy of _Osteocephalus_ was unchallenged until only a decade ago. Goin (1961) presented a generic synopsis of the genera of hylid frogs, in which he recognized _Osteocephalus_ and stated: "There are perhaps eight or ten species of this genus in South America. Certainly _taurinus_, _britti_, _leprieuri_, _buckleyi_ and _pearsoni_ belong here. _O. planiceps_ is surely a synonym of _leprieuri_ and I believe that _garbei_ is as well. The status of such forms as _macrotis_, _riopastazae_, and _depressa_ has not yet been settled." Goin defined _Osteocephalus_ as follows: "Males with paired vocal pouches, one at each angle of the jaw; derm of head not co-ossified with skull but roof of skull exostosed." Trueb (1970a) elaborated on Goin's definition and assuredly included only _O. taurinus_ and _O. leprieurii_ in the genus. Goin's inclusion of _buckleyi_, _britti_, and _pearsoni_ in _Osteocephalus_ was the first association of any of these names with that genus. Duellman (1970a) demonstrated that _Garbeana garbei_ Miranda-Ribeiro, 1926, was a member of the _Hyla rubra_ group. _Hyla macrotis_ Andersson, 1945, is a _Phrynohyas_. Trueb and Duellman (1970) determined that _Hyla verrucigera_ Werner, 1901, is the earliest name for an _Osteocephalus_ displaying striking sexual dimorphism in coloration and texture of the dorsal skin; _Hyla riopastazae_ Andersson, 1945 (female holotype), and _Hyla orcesi_ Funkhouser, 1956 (male holotype), were placed in the synonymy of _Osteocephalus verrucigerus_. _Hyla pearsoni_ Gaige, 1929, is a small species of _Osteocephalus_. Our findings substantiate Goin's suggestions relative to two other taxa. _Hyla leprieurii britti_ Melin, 1941, from the Rio Uaupés, Brasil, and _Hyla depressa_ Andersson, 1945, from the Río Pastaza watershed, Ecuador, are members 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, Brasil, also is placed in the synonymy of _O. taurinus_. Cochran and Goin (1970) were unaware of the identities of _Hyla verrucigera_ and _riopastazae_; they used the later name _Osteocephalus orcesi_ for Colombian frogs that are correctly referred to _O. verrucigerus_. Although Goin (1961) placed _Hyla buckleyi_ and _H. pearsoni_ in _Osteocephalus_, Cochran and Goin (1970) recognized a "_buckleyi_ group" in _Hyla_ that included these two species plus a new species, _Hyla cabrerai_ from Amazonian Colombia and Brasil (total of three specimens). Also, these authors named _Hyla carri_ from a single Colombian specimen. Study of the types of _Hyla cabrerai_, _H. carri_, and _H. festae_ Peracca, 1904, from Ecuador, reveal that all of these names are synonyms of _Osteocephalus buckleyi_. Much of the taxonomic confusion and multiplicity of trivial names is due to the great amount of color variation in _taurinus_ and to the sexual dimorphism in the texture of the dorsal skin in all of the species. The details of variation in these and other characters and our justifications for the synonymies are given in the accounts of the species. All of the trivial names that apply to species herein recognized as members of the genus _Osteocephalus_ are listed in table 1. =Osteocephalus= Steindachner, 1862 _Osteocephalus_ Steindachner, 1862:77 [Type species.--_Osteocephalus taurinus_ Steindachner, 1862, by original designation]. Not _Osteocephalus_ Fitzinger, 1843:50 (_nomen nudum_). _Diagnostic Definition._--1) Skull broader than long; 2) dermal roofing bones of skull well ossified, exostosed, and/or co-ossified in some species; 3) prenasal and internasal bones absent; 4) parasphenoid alae posterolaterally oriented; 5) dentigerous processes of prevomers angular (/--\); 6) vocal sacs paired, posterior, and when inflated protruding posteroventral or posterolateral to angles of jaws; 7) submentalis muscle moderate in size and araphic; 8) intermandibularis muscle undifferentiated and bearing an elongate median aponeurosis; 9) parotoid glands absent or poorly developed, skin not producing viscous secretion characteristic of _Phrynohyas_; 10) skin on dorsum tuberculate in males, smooth in females; 11) tympanum large, 60 percent or more of diameter of eye; 12) fingers about one-third, toes more than three-fourths webbed; 13) discs large, round; 14) nuptial excrescences present in breeding males; 15) inner metatarsal tubercle not modified for digging; 16) outer metatarsal tubercle absent; 17) tarsal fold weak or absent; 18) pupil horizontal; 19) palpebrum clear; 20) known tadpoles having two upper and five lower rows of teeth. TABLE 1.--Alphabetical Synonymy of the Species of _Osteocephalus_. Trivial Name, Original Generic Name, Author, Date Current Name ---------------------------------------------------------------------- _britti (Hyla leprieurii)_ Melin, 1941 _O. leprieurii_ _buckleyi (Hyla)_ Boulenger, 1882 _O. buckleyi_ _cabrerai (Hyla)_ Cochran and Goin, 1970 _O. buckleyi_ _carri (Hyla)_ Cochran and Goin, 1970 _O. buckleyi_ _depressa (Hyla)_ Andersson, 1945 _O. taurinus_ _festae (Hyla)_ Peracca, 1904 _O. buckleyi_ _flavolineatus (Osteocephalus)_ Steindachner, 1862 _O. taurinus_ _leprieurii (Hyla)_ Duméril and Bibron, 1841 _O. leprieurii_ _orcesi (Hyla)_ Funkhouser, 1956 _O. verrucigerus_ _pearsoni (Hyla)_ Gaige, 1929 _O. pearsoni_ _planiceps (Osteocephalus)_ Cope, 1874 _O. taurinus_ _riopastazae (Hyla)_ Andersson, 1945 _O. verrucigerus_ _taurinus (Osteocephalus)_ Steindachner, 1862 _O. taurinus_ _verrucigera (Hyla)_ Werner, 1901 _O. verrucigerus_ _vilarsi (Hyla)_ Melin, 1941 _O. taurinus_ _Content._--As defined here, the genus contains 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 localities are at elevations below 500 m, but the genus ascends the Amazonian slopes of the Andes to elevations of about 1800 m. ANALYSIS OF CHARACTERS _Size and Proportions._--Frogs of the genus _Osteocephalus_ are moderate to large hylids. The largest species is _taurinus_, attaining a snout-vent length of 103.1 mm; the smallest is _pearsoni_, which attains a length of 54.7 mm. Considerable intraspecific geographic variation occurs in adult size, especially in _taurinus_. Females of all species attain a noticeably larger size than males, but no significant differences are apparent in proportions (Table 2). TABLE 2.--Comparison of Size and Proportions in the Species of _Osteocephalus_. (Means are given in parentheses below observed ranges) ======================================================================================================== Species N Snout-vent Tibia Length/ Foot Length/ Head Length/ Head Width/ Tympanum/ Length S-V L S-V L S-V L S-V L Eye -------------------------------------------------------------------------------------------------------- _O. buckleyi_ [M] 30 37.9-48.1 0.478-0.580 0.375-0.444 0.319-0.357 0.329-0.368 0.608-0.820 (43.3) (0.520) (0.408) (0.343) (0.351) (0.711) [F] 31 48.6-75.1 0.476-0.599 0.363-0.469 0.310-0.358 0.318-0.367 0.574-0.905 (61.7) (0.553) (0.428) (0.333) (0.348) (0.734) _O. leprieurii_ [M] 21 41.2-48.4 0.514-0.571 0.383-0.430 0.308-0.357 0.326-0.368 0.652-0.884 (44.7) (0.538) (0.408) (0.335) (0.348) (0.777) [F] 21 46.6-61.5 0.516-0.592 0.382-0.453 0.314-0.343 0.328-0.363 0.698-0.909 (57.1) (0.539) (0.404) (0.329) (0.349) (0.785) _O. pearsoni_ [M] 2 45.3-46.2 0.481-0.504 0.404-0.437 0.322-0.335 0.327-0.342 0.660-0.673 (45.8) (0.493) (0.421) (0.329) (0.335) (0.666) [F] 1 54.7 0.521 0.405 0.318 0.346 0.862 _O. taurinus_ [M] 59 40.3-84.6 0.512-0.576 0.387-0.445 0.296-0.345 0.301-0.355 0.638-0.896 (66.3) (0.541) (0.416) (0.318) (0.324) (0.752) [F] 45 45.1-103.1 0.520-0.577 0.391-0.448 0.306-0.334 0.308-0.347 0.640-0.817 (75.8) (0.542) (0.420) (0.321) (0.327) (0.758) _O. verrucigerus_ [M] 11 50.4-54.3 0.494-0.552 0.409-0.442 0.322-0.346 0.328-0.344 0.623-0.804 (53.0) (0.519) (0.427) (0.333) (0.337) (0.730) [F] 3 63.1-65.8 0.532-0.561 0.435-0.463 0.345-0.347 0.348-0.379 0.692-0.808 (64.5) (0.545) (0.448) (0.346) (0.358) (0.731) -------------------------------------------------------------------------------------------------------- _Coloration._--All _Osteocephalus_ are predominantly brown frogs usually with some darker dorsal markings (Figs. 1 and 2). _Osteocephalus verrucigerus_ has a nearly uniform dark brown dorsum and no distinct transverse bars on the limbs, whereas all of the other species have distinct bars on the limbs. The dorsal markings on the body consist of irregular blotches in _buckleyi_, _pearsoni_, and _taurinus_ but are narrow transverse marks in _leprieurii_. A narrow middorsal cream or yellow stripe is present in some individuals of _buckleyi_ and _taurinus_ but absent in all individuals of the other species. The flanks are uniform pale tan in _leprieurii_ and uniform reddish brown in _verrucigerus_; in the other species the flanks are cream to brown with dark brown or black spots (also dark diagonal marks in some _buckleyi_). A creamy white anal stripe is present in some specimens of _leprieurii_ but absent in all individuals of other species. The postocular region, encompassing the tympanum, is dark brown in most specimens. In adults of _pearsoni_ and _taurinus_ the upper lips are dark brown. A pale cream or tan suborbital spot is present in _pearsoni_ and in some _taurinus_; in some specimens of _taurinus_ the suborbital spot is expanded posteriorly forming a labial stripe on the posterior part of the lip. The labial markings of _verrucigerus_ are similar to the latter pattern, except that in females a distinct, light labial stripe extends the length of the lip. _Osteocephalus leprieurii_ has a distinct, broad, pale labial stripe. The lips are barred cream and dark brown in _buckleyi_. The venter is uniform creamy white or pale tan in _leprieurii_, uniform white in some _buckleyi_ (most males), and uniform tan in some _taurinus_. The other species and some individuals of _taurinus_ and _buckleyi_ (most females) have dark ventral markings. These markings are most distinctive in _verrucigerus_, in which the venter is white with bold black mottling and spots (Fig. 3c). Those individuals of _taurinus_ having ventral markings usually have indistinct, diffuse brown spots on the throat and chest (Fig. 3b). _Osteocephalus pearsoni_ is characterized by a fine brown reticulation on the venter and on the anterior and posterior surfaces of the thighs in adults (Fig. 3a). Individuals of _buckleyi_ that have ventral markings vary between the patterns illustrated for _pearsoni_ and _taurinus_ (Figs. 3b and c). Ontogenetic change in coloration is slight or non-existent in _buckleyi_, _pearsoni_, and _taurinus_, except that juveniles lack ventral markings. A dark blotch on the back and distinct transverse bars on the limbs are evident in juveniles of _verrucigerus_; these markings are obscured in the adults. Juveniles of _leprieurii_ are olive-brown with yellow dorsolateral stripes; the transverse dark marks, characteristic of the adults, appear before the stripes are lost. [Illustration: FIG. 1. Species of _Osteocephalus_: Top. _O. pearsoni_, KU 136312, [M]; Middle. _O. buckleyi_, KU 123172, [M]; Bottom. _O. verrucigerus_, KU 123177, [M]. ×1.5.] [Illustration: FIG. 2. Species of _Osteocephalus_: Top. _O. leprieurii_, KU 126611, [F]; Bottom. _O. taurinus_, KU 126648, [M]. ×1.] [Illustration: FIG. 3. Diagrammatic views of ventral color patterns in _Osteocephalus_: a. _O. pearsoni_, UMMZ 57533, [M]; b. _O. taurinus_, USNM 166037, [M]; c. _O. verrucigerus_, KU 123185, [F].] _Skin._--The dorsal skin of all males of _Osteocephalus_ is tuberculate to varying degrees, whereas the dorsal skin of females is smooth, or nearly so (Fig. 4). _Osteocephalus verrucigerus_ differs from other members of the genus by the presence of numerous, large tubercles bearing keratinized tips. The tubercles of _leprieurii_ are numerous and spinous but much smaller than those of _verrucigerus_; those of _taurinus_ are spinous but less numerous than in _leprieurii_. _Osteocephalus buckleyi_ has a mixture of large and small, non-spinous tubercles, and _pearsoni_ has only a few, small, scattered, non-spinous tubercles. Fleshy tubercles occur on the eyelids and supratympanic fold in females of _buckleyi_; a few small tubercles are present on the back of females of _pearsoni_, whereas the dorsal skin in females of the other species is smooth. The skin on the flanks of both sexes of _buckleyi_ is weakly areolate; in the other species the flanks are smooth. The skin on the top of the head in _taurinus_ is rugose as a consequence of co-ossification. In all species the anal opening is directed posteriorly at the upper level of the thighs. _Hands and Feet._--The feet of _Osteocephalus_ are fully webbed or nearly so. Webbing between fingers one and two is basal in all species. Webbing between fingers two, three, and four is most extensive in _taurinus_, in which the three fingers are about one-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 members of the genus have well-developed subconical subarticular tubercles on the fingers and toes; there is a tendency for the distal tubercle on the fourth finger to be weakly bifid. Palmar and plantar supernumerary tubercles are well developed in _taurinus_, moderately developed in _buckleyi_, _leprieurii_, and _pearsoni_, and barely evident in _verrucigerus_. All of the species have a noticeable fold on the wrist and enlarged prepollices, bearing 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 ovoid in _leprieurii_ and _pearsoni_; it is elliptical and flat in the other species. Tarsal folds are absent in all species except _verrucigerus_, in which the folds are barely evident. [Illustration: FIG. 4. Segments of dorsal skin of males of _Osteocephalus_ showing size and arrangement of tubercles: a. _O. verrucigerus_, KU 123183; b. _O. taurinus_, USNM 166033; c. _O. leprieurii_, KU 126616; d. _O. buckleyi_, USNM 165999. Each square = 1 sq. cm.] _Cranium._--As a genus, the cranial structure is remarkably uniform and quite generalized when viewed in the context of the family Hylidae. The skulls are broad and relatively flat, each being only slightly more broad than long and about one-third as high as long. In dorsal aspect the snouts are broadly rounded; the snout of _buckleyi_ is somewhat less rounded and appears to be slightly longer than the snouts of other species. This subtle difference relates to the relative narrowness of the premaxillaries in _buckleyi_. [Illustration: FIG. 5. Palmar views of hands of males of _Osteocephalus_: a. _O. buckleyi_, KU 109506; b. _O. leprieurii_, KU 126627; c. _O. pearsoni_, MCZ 15565; d. _O. taurinus_, KU 126653; e. _O. verrucigerus_, KU 123177. ×4.] [Illustration: FIG. 6. Skulls of two species of _Osteocephalus_: a and b. _O. leprieurii_, KU 125961; c and d. _O. pearsoni_, UMMZ 67465. ×3.] The genus is characterized by well-developed dermal roofing bones and an unusually large exposure of the sphenethmoid dorsally (Fig. 6). The conformation of the sphenethmoid exposed dorsally is determined by the marginal positions of the adjacent, overlapping elements--the nasals and frontoparietals. Medially the nasals overlap the lateral margins of the sphenethmoid. Anteromedially, the nasals converge in _leprieurii_ and _taurinus_, are narrowly separated in _buckleyi_ and _pearsoni_, or are more widely separated in _verrucigerus_. In all species the nasals terminate at the anterodorsal corner of the orbit. The frontoparietals of _buckleyi_, _leprieurii_, and _taurinus_ have an anterolateral extension, which marginally overlaps the dorsolateral edge of the sphenethmoid and articulates with the posterodorsal corner of the nasal in _buckleyi_ and _taurinus_; the bones are narrowly separated in _leprieurii_. The frontoparietals of _pearsoni_ and _verrucigerus_ have more extensive median ossification and less extensive anterolateral ossification. Thus, in those species the posteromedian portion of the sphenethmoid is obscured, and the lateral margins are partly exposed. The frontoparietal fontanelle is completely covered in all species, except _buckleyi_ and _leprieurii_, in which an irregular, median separation of the frontoparietals exposes a small portion of the fontanelle. The posterolateral margins of the frontoparietals lie medial to the epiotic eminences. Dermal ornamentation, involving the nasals, frontoparietals, and sphenethmoid, occurs in _taurinus_ and, to a limited extent, in _pearsoni_. In the latter species marginal portions of the frontoparietals, the dorsal surfaces of the nasals, and the posteromedial part of the exposed sphenethmoid are slightly exostosed, resulting in an open, reticulate pattern of dermal sculpturing of exceedingly low relief (Fig. 6c). _Osteocephalus taurinus_ is characterized by casquing, co-ossification, and a rather intricate pattern of dermal sculpturing, which was described in detail and illustrated by Trueb (1970a). The squamosals of all species are moderately large structures having otic plates that overlie the lateral portion of the cristae paroticae. The posterior rami are short; the zygomatic rami of all species, except _taurinus_, extend slightly more than one-half of the distance to the maxillary. In _taurinus_ the zygomatic ramus extends nearly to, or articulates with, the maxillary. The maxillary arches are complete and relatively robust. The alary processes of the premaxillaries are vertically oriented in _leprieurii_, _pearsoni_, and _taurinus_ and very slightly inclined posteriorly in _buckleyi_ and _verrucigerus_. The maxillaries are uniformly characterized by the absence of postorbital processes and by the presence of preorbital processes that articulate with the maxillary processes of the nasals. The partes facialae of the maxillaries are moderately developed in all species, except _taurinus_, in which the pars fascialis tends to articulate with the lateral margin of the nasal in well-ossified individuals. The partes palatinae are poorly developed in all species, except _buckleyi_, in which the pars palatina of the premaxillary is moderately robust. The pterygoids are uniformly tri-radiate structures. The anterior rami terminate at about the mid-level of the orbit, and the medial rami articulate firmly with the anterolateral corner of the otic capsule. The palatines are well-developed elements bearing ventral ridges; the ridges are somewhat irregular in _buckleyi_, _taurinus_, and _verrucigerus_ but smooth in _leprieurii_ and _pearsoni_. The parasphenoids are large elements characterized by acuminate cultriform processes and posterolaterally inclined alary processes. The basal areas of the cultriform processes bear small odontoid protuberances in _buckleyi_, _taurinus_, and _verrucigerus_, whereas they are smooth in _leprieurii_ and _pearsoni_. The prevomers are remarkably uniform, moderately well-developed structures. In each species the anterior ramus lies adjacent to the premaxillary, and the lateral wings form the anterior, medial, and posteromedial margins of the internal nares. The dentigerous processes are characteristically large and angular and bear numerous teeth. The sphenethmoid and otoccipitals are well ossified; a dermal sphenethmoid is present only in _taurinus_. [Illustration: FIG. 7. Dorsal views of vertebral columns of two species of _Osteocephalus_: a. _O. leprieurii_, KU 125962, [F]; b. _O. buckleyi_, USNM 165997, [F]. ×2.] _Vertebral Column._--The cervical cotyles are uniformly widely displaced. The neural arches are low and non-imbricate. The transverse processes of the third presacral vertebrae are approximately equal in width to the sacral diapophyses in all species, except _buckleyi_, in which the processes of the third presacral are slightly narrower than the diapophyses. _Osteocephalus buckleyi_ is further distinguished by the presence of narrow transverse processes on presacrals five through eight (Fig. 7b); males have narrower processes than do females. The processes are moderately wide but subequal in width in _pearsoni_, _taurinus_, and _verrucigerus_, whereas they are nearly equivalent in width to one another and to the sacral diapophyses in _leprieurii_ (Fig. 7a). The sacral diapophyses of all species are moderately dilated and posterolaterally inclined. The coccyx bears a distinct dorsal ridge and has a bicondylar articulation with the sacrum. _Pectoral Girdle._--The pectoral girdles are fully arciferal and bear small, cartilaginous omosterna and moderately large cartilaginous sterna. The coracoids are robust, and the clavicles are strongly arched. Procoracoid cartilage seems to be absent. The scapulae are large, longer than the clavicles, and bicapitate proximally. The suprascapulae are moderately large and well ossified in _leprieurii_ and _taurinus_. The suprascapula of _verrucigerus_ is poorly ossified, and that of _buckleyi_ is not ossified. _Pelvic Girdle._--The ilia of _buckleyi_, _taurinus_, and _verrucigerus_ lack any indication of a crest on the shaft, whereas _leprieurii_ has a low crest. The dorsal acetabular expansion of the ilia is moderately low in _taurinus_ and _verrucigerus_, but distinctly lower in _buckleyi_ and _leprieurii_. The ilia of all species bear low dorsal protuberances. The ischia of _leprieurii_, _taurinus_, and _verrucigerus_ are moderately expanded; that of _buckleyi_ is somewhat less expanded dorsally. The pubis of _leprieurii_, _taurinus_, and _verrucigerus_ are calcified, whereas that of _buckleyi_ remains cartilaginous. _Throat Musculature and Vocal Sac Structure._--Tyler (1971) described the throat myology of _Osteocephalus_. The genus is characterized by a moderate-sized araphic submentalis muscle and an undifferentiated intermandibularis having an elongate median aponeurosis. The intermandibularis and submentalis are completely independent in _buckleyi_, whereas in the other species there is a small attachment between these muscles. According to Tyler (pers. com.), _Osteocephalus_ has three distinctive types of vocal sac structure which result from differences in the development of the interhyoideus muscle and the overlying skin. In _leprieurii_ and _verrucigerus_ the supramandibular portions of the interhyoideus form a simple tubular, posterolateral extension; there is no modification of the associated skin. _Osteocephalus buckleyi_ and _pearsoni_ have more extensive development of the supramandibular portions of the interhyoideus; furthermore, the associated skin forms a broad, loose fold extending from the ventromedial surface of the throat dorsolaterally to the base of the supratympanic fold. Like _buckleyi_ and _pearsoni_, the supramandibular portion of the interhyoideus is much expanded in _taurinus_. The vocal sac structure of _taurinus_ differs from that of other members of the genus in that the skin of _taurinus_ forms an everted pouch, which dangles loosely beneath the supratympanic fold. KEY TO THE SPECIES OF _Osteocephalus_ 1. Inner edge of third finger webbed to mid-length of antepenultimate phalange; dorsum brown with dark brown spots or median blotch; skull in adults casqued and co-ossified with prominent supraorbital flanges _O. taurinus_ Inner edge of third finger webbed to base of antepenultimate phalange; dorsum plain or marked with dark blotches or transverse bars; skull in adults smooth or slightly exostosed, lacking supraorbital flanges 2 2. Skin on flanks areolate; dorsum in males bearing a mixture of large and small non-spinous tubercles; lips distinctly barred _O. buckleyi_ Skin on flanks smooth; dorsum in males bearing tubercles of uniform size; lips not barred 3 3. Dorsal pattern consisting of narrow transverse dark bars; dorsum in males bearing numerous small spinous tubercles _O. leprieurii_ Dorsal pattern not consisting of transverse bars; dorsal tubercles large or few in number 4 4. Dorsum uniformly dark brown; venter heavily mottled with black, especially in females; dorsum in males bearing large, keratinized tubercles _O. verrucigerus_ Dorsum tan with irregular dark brown blotches; venter cream with fine brown reticulations; dorsum in males bearing few, small non-spinous tubercles _O. pearsoni_ ACCOUNTS OF SPECIES =Osteocephalus buckleyi= (Boulenger) _Hyla buckleyi_ Boulenger, 1882:362 [Syntypes.--BMNH 1947.2.13.36-39 from Sarayacu, Provincia Pastaza, Ecuador; BMNH 1947.2.13.40-41, 1947.2.13. 43-45 from Canelos, Provincia Pastaza, Ecuador; BMNH 1947.2.13.46 from "Paitanga" (= Pallatanga), Provincia Chimborazo, Ecuador (in error); Mr. Buckley collector; BMNH 1947.2.13.44 here designated as lectotype]. _Hyla festae_ Peracca, 1904:39 [Holotype.--MIZS 2950 from "Valle de Santiago" (= lower Río Zamora), Provincia Morona-Santiago, Ecuador; Enrico Festa collector]. New synonymy. _Osteocephalus buckleyi_--Goin, 1961:13. _Hyla carri_ Cochran and Goin, 1970:211 [Holotype.--FMNH 69702 from Acevedo, Río Suaza, Departamento Huila, Colombia; Philip collector]. New synonymy. _Hyla cabrerai_ Cochran and Goin, 1970:215 [Holotype.--USNM 152759 from Caño Guacayá, tributary of lower Río Apoporis, Comisaria Amazonas, Colombia; Isadore Cabrera collector]. New synonymy. _Justification of Synonymy._--Boulenger (1882:362) listed 11 specimens in his description of _Hyla buckleyi_. We have examined all of these and conclude that one (BMNH 1947.2.13.42) is _O. leprieurii_. Cochran and Goin (1970:213) restricted the type locality to Canelos, Provincia Pastaza, Ecuador; we here select BMNH 1947.2.13.44 from that locality as the lectotype. This specimen is a male having a snout-vent length of 37.9 mm; the diameter of the tympanum is 3.5 mm, 81.4 percent of the diameter of the eye. The type series, exclusive of BMNH 1947.2.13.42 (=_O. leprieurii_) consists of six males having snout-vent lengths of 37.9-44.6 (mean 40.4) mm, and four females having snout-vent lengths of 50.0-53.9 (mean 51.5) mm. The dorsum in the males bears a mixture of large and small tubercles, whereas the dorsum in females is nearly smooth. The skin on the flanks, especially the axilla, is areolate. The coloration consists of a creamy tan ground color 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 consist of an interorbital bar and a pair of longitudinal marks beginning in the scapular region and usually diverging posteriorly in the sacral region or converging into a broad median blotch. One specimen has a middorsal creamy white stripe from the tip of the snout to the vent. In all of the types large dark brown spots are present on the flanks and posterior surfaces of the thighs. The ventral surfaces are pale creamy tan with or without diffuse brown spots on the throat and chest. The holotype of _Hyla festae_ is a female having a snout-vent length of 75.0 mm; the diameter of the tympanum is 3.9 mm, 57.4 percent of the diameter of the eye. The skin is smooth on the dorsum and areolate on the anterior part of the flanks. The dorsum is pale brown with a large median longitudinal dark brown blotch on the back and broad transverse bars, narrowly outlined by cream, on the limbs. Dark brown spots are present on the flanks; the posterior surfaces 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 having a snout-vent length of 66.1 mm; the diameter of the tympanum is 4.7 mm, 81.0 percent of the diameter of the eye. The skin on the dorsum is smooth with scattered small tubercles and areolate on the anterior part of the flanks. The dorsum is tan with irregular dark brown blotches on the back and transverse bars on the limbs; all dorsal markings are narrowly outlined by creamy white. Dark brown spots are present on the flanks; the venter and posterior surfaces of the thighs are tan without dark spots. The holotype of _Hyla cabrerai_ is a female having a snout-vent length of 52.7 mm; the diameter of the tympanum is 4.0 mm, 76.9 percent of the diameter of the eye. The skin on the dorsum is weakly tuberculate and that on the anterior part of the flanks is areolate. The dorsum is creamy tan with dark brown markings (interorbital bar, reticulations on occiput, three longitudinal streaks on back, and broad transverse bars on limbs). Irregular dark brown spots are present on the flanks. The venter is 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) stated: "This species, together with _buckleyi_ and _pearsoni_ certainly make a closely knit group.... Both _buckleyi_ and _cabrerai_ have long hind legs, with the extended heel reaching to the tip of the snout, while in _pearsoni_ the extended heel reaches only to the eye. _H. buckleyi_ has the belly dusky, while it is heavily spotted in _cabrerai_ and is reticulated in _pearsoni_. _H. cabrerai_ seems to have the heaviest hands with the most webbing between the fingers; the other two species have the webbing reduced between the fingers." The description of _Hyla cabrerai_ was based on three specimens. We have examined the holotype and one paratype (WCAB 13284 from Territorio do Amapá, Brasil). Another paratype in the private collection of C. J. Goin from 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 gravid female and stated: "A large _Hyla_ with the vomerine teeth in two ^^ shaped patches between the somewhat squarish choanae; reduced webs between the fingers; and a pattern of dorsal dark blotches bordered by light margins. The species is not similar to any other species known in Colombia. It is perhaps most closely related to _Hyla claresignata_ of Brazil, from which it can be differentiated by its more heavily spotted dorsum, larger tympanum, and lack of dark anal spots." Except for the inclusion of the name in checklists, _Hyla festae_ has not been mentioned in the literature since the original description. The wholesale synonymization of names, which, on the bases of their published diagnoses, seem to apply to distinctly different species, is possible with the application of uniform criteria to the types and series of other specimens. In measurements and proportions the type specimens of the nominal taxa all fall within the range of variation exhibited by a series of 18 males and 15 females from Provincia Pastaza, Ecuador, except 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, whereas the ratio in the 15 females from Provincia Pastaza is 0.587-0.905 (mean 0.736). Ventral coloration is the most variable character among the types. The venter in the type of _Hyla festae_ is boldly 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 series of specimens from Amazonian Ecuador encompasses that observed in all of the types, except that of _festae_, which has more ventral spotting than any other individual. The webbing on the hand usually excludes the penultimate phalanges of the fingers, but in some specimens from Amazonian Ecuador the webbing encompasses the proximal parts of the penultimate phalanges of the fingers. In a few of these specimens, the holotype of _festae_, and one paratype of _cabrerai_ the webbing extends to the middle of the penultimate phalanges of the third and fourth fingers. In the holotype of _cabrerai_ the webbing extends to the middle of the penultimate phalanges of the third and fourth fingers and to the base of the disc of the second finger. The types of the nominal taxa and series of specimens from Guyana and Amazonian Ecuador display noticeable variation in dorsal coloration. The variety of dorsal patterns of all of the types is included in the variation displayed by the other specimens. All specimens have some amount of dark spotting on the flanks; all have vertically barred lips, on which a pale subocular spot usually is evident. Probably the most unifying physical characteristic of all of the specimens is the nature of the skin on the anterior part of the flank. The skin is elevated amidst an irregular network of depressions. This areolate dermal condition is present in all specimens and does not occur in other species of _Osteocephalus_. The degree of tubercularity of the skin on the dorsum is variable and sexually dimorphic. All males are tubercular, whereas small females are smooth or have only a few scattered tubercles. Large females usually have pronounced tubercles on the eyelids and supratympanic fold. In their description of _Hyla carri_, Cochran and Goin (1970:211) misrepresented the nature of the dentigerous processes of the prevomers, which are angular, not ^-shaped. Their suggestion that the Colombian _Hyla carri_ is related to _Hyla claresignata_ in southeastern Brasil is unfounded. The latter species is smaller (40 mm), has a yellow dorsum and venter, dark brown spots dorsolaterally, oblique dentigerous processes of the prevomers, small tympanum, and smooth skin dorsally. The ventral coloration of the type of _Hyla festae_ resembles that of _Osteocephalus verrucigerus_, but the type differs from _verrucigerus_ by having areolate skin on the flanks and distinct dark markings on the dorsum. In _verrucigerus_ the skin on the flanks is smooth, and the dorsum is uniform dark brown, except for a tan snout in females. Comparisons of the types of the nominal species with series of specimens from Guyana, Colombia, Ecuador, and Perú suggest strongly that the types are representative of one taxon, the oldest name for which is _Hyla buckleyi_ Boulenger, 1882. Consequently, we place _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 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. [Illustration: FIG. 8. Distribution of _Osteocephalus buckleyi_ (circles) and _O. pearsoni_ (triangles).] _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. [Illustration: FIG. 9. Distribution of _Osteocephalus leprieurii_ (circles) and _O. verrucigerus_ (triangles).] _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. [Illustration: FIG. 10. Ontogenetic change in color pattern in _Osteocephalus leprieurii_: a. KU 126644; b. KU 126640; c. KU 126625. ×2.] 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. The type of _Hyla depressa_ is a male having a snout-vent length of 69.8 mm. The diameter of the tympanum is 5.2 mm, 77.6 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 elevated. The skin on the dorsum is tuberculate. The dorsum is dull brown with a broad darker brown longitudinal mark having indistinct lateral edges from the snout to the post-sacral area. A narrow cream middorsal line extends from the snout to the vent. The side of the head is dark brown, palest posteroventral to the orbit. The posterior surfaces of the thighs are dull brown; the flanks are pale brown, and the ventral surfaces are pale creamy tan. Dark brown transverse bars are present on the limbs. When we examined the type on 3 January 1969, it was in excellent condition. Andersson (1945:75) contrasted the type of _Hyla depressa_ with _leprieurii_ and _buckleyi_, but he did not compare his specimen with _taurinus_, from which it exhibits no distinguishing features. _Osteocephalus taurinus_ is a widespread and variable species, and it has received several specific names. We are convinced that _Osteocephalus taurinus_ Steindachner, 1862, is the oldest available name for this large Amazonian species. 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) Size large; sexual dimorphism evident; maximum observed snout-vent length in males 84.6 mm, in females 104 mm; 2) skin on dorsum in males bearing many moderately large, spinous tubercles; 3) skin on flanks smooth; 4) web extending to middle of antepenultimate phalange on inner edge of third finger; 5) dorsum brown usually with a large medial dark brown blotch or, less frequently, several dark spots; narrow middorsal yellow line present in some; 6) venter cream or tan with or without small, irregular brown flecks; 7) lips brown with vertical cream bar below eye in some, expanded into pale labial stripe posteriorly in some females; 8) flanks tan or cream with or without small, irregular brown spots; 9) dermal roofing bones of skull exostosed, casqued, and co-ossified (in large adults); 10) dermal sphenethmoid present; 11) nasals juxtaposed medially; 12) anteromedial margin of frontoparietals at mid-level of orbit; 13) frontoparietal fontanelle covered; 14) palatine serrate; 15) parasphenoid bearing odontoids; 16) zygomatic ramus of squamosal usually articulating with 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 everted pouch. The moderately rugose dorsum (in males), large size, extensive webbing on the hand, and frontoparietal flanges in adults serve to distinguish _taurinus_ from other members of the genus. _Distribution._--The Amazon Basin, the upper Orinoco Basin, and the Guianas. Most localities are below 500 m, but the species ascends the lower Amazonian slopes of the Andes to elevations of about 1000 m (Fig. 11). A record from Caracas, Venezuela, and those from Provincia Carchi and Provincia Esmeraldas, Ecuador, are considered to be erroneous. The latter specimens were included in a collection sold to the University of Illinois; contained in the collection are many common Amazonian species unknown from the Pacific lowlands. 516 specimens from 151 localities. [Illustration: FIG. 11. Distribution of _Osteocephalus taurinus_.] _Remarks._--This widespread species is highly variable in size and coloration. Striking differences in snout-vent length are evident in series from various parts of the range. The smallest calling males (CAS-SU 12351-6 from Rio Tapirapé, Brasil) have snout-vent lengths of 46.5-60.3 (mean 53.3) mm, whereas the largest (FMNH 140254, KU 92243-6, WCAB 9997, 10001, 10003-4 from Igarapé Marmelo, Brasil) have snout-vent lengths of 71.5-84.6 (mean 77.6) mm. Mean values of snout-vent lengths of males from other localities are: 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 highly significant, populations bridging the gap do exist. Furthermore, the geographic arrangement of small versus large frogs is a confusing mosaic. We have entertained the thought that we have included more than one species in _taurinus_, but on the basis of preserved specimens we are unable to detect consistent differences distinguishing two or more taxa. The coloration and pattern of _taurinus_ are so variable that no one series of statements can describe samples drawn from the entire range of species. We have been unable to determine geographic trends in color pattern; instead the variation within a given sample can encompass the variety known in most other samples. Two minor exceptions do exist. A narrow middorsal light stripe is present in some individuals from throughout the range, but striped specimens are most common in the upper Amazon Basin. The absence of dorsal markings is uncommon in the entire species, but it is most frequent in individuals from the Guianas. A few individuals, such as KU 105230, have scattered white spots on the dorsum. The coloration of four males in life from Lago Agrio, Ecuador (KU 126652-5) was: "Dorsal ground color tan to dark brown with darker brown markings. Flanks creamy tan to yellow with brown or black flecks or mottling. Venter uniform creamy yellow or yellow with brown spots or reticulations. Iris 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), was: "Dorsum mottled olive-green and tan. Flanks tan with brown spots. Belly and throat creamy white, becoming tan posteriorly. Edge of upper jaw olive-green." (W. E. Duellman, field notes, 16 June 1968.) Another female from Santa Cecilia (KU 123175), was: "Brown dorsally with cream-colored mottling. Transverse bars on legs darker brown with cream-colored edges. Margin of upper lip creamy yellow. Anterior and posterior surfaces of thighs tan. Flanks white with brown spots. Venter creamy white. Iris greenish bronze with heavy radiating reticulations of black." (W. E. Duellman, field notes, 22 July 1968.) The tendency for females to have a labial stripe posteriorly and the absence of dorsal tubercles in females has resulted in the identification of many such specimens as _O. leprieurii_. Ontogenetic change in coloration is slight in _taurinus_. Most juveniles (less than 40 mm in snout-vent length) can be identified readily. There is a tendency for the dorsal markings of juveniles to consist of several small spots. Apparently with growth the spots usually coalesce, forming a large median blotch, but some adults retain the juvenile pattern. Cochran and Goin (1970:251) erroneously identified several juveniles from Colombia as _Hyla palpebrogranulata_ Andersson. =Osteocephalus verrucigerus= (Werner) _Hyla verrucigera_ Werner, 1901:601 [Holotype.--ZMB 16589 from "Ecuador"; Richard Haensch collector]. _Hyla riopastazae_ Andersson, 1945:72 [Holotype.--NHRM 1960 from Baños, Río Pastaza, Provincia Tungurahua, Ecuador; William Clarke-MacIntyre collector]. _Hyla orcesi_ Funkhouser, 1956:78 [Holotype.--CAS-SU 13150 from Río Pacayacu, tributary of Río Cotapino, Provincia Napo, Ecuador; collector unknown]. _Osteocephalus orcesi_--Cochran and Goin, 1970:317. _Osteocephalus verrucigerus_--Trueb and Duellman, 1970:601 [Synonymized _Hyla riopastazae_ Andersson, 1945, and _Hyla orcesi_ Funkhouser, 1956, with _Hyla verrucigera_ Werner, 1901]. _Justification of Synonymy._--Trueb and Duellman (1970:605) discussed the assignment of the names in the synonymy of _O. verrucigerus_; only a brief resumé is given here. The extant type of _Hyla verrucigera_ is a juvenile male having a snout-vent length of 32.0 mm. The dorsum is smooth except for tubercles on the eyelids; the skin is loose, and the body is soft. The specimen is faded to a pale brown; indistinct dark spots are present on the back, and transverse bars are evident on the limbs. The holotype of _Hyla riopastazae_ is a gravid female having a snout-vent length of 64.7 mm. The dorsum is smooth. The dorsal ground color is pale brown with indistinct brown transverse bars on the limbs. The throat, chest, and belly are cream with brown spots and mottling. The holotype of _Hyla orcesi_ is an adult male having a snout-vent length of 52.6 mm. The dorsum is heavily tuberculate. The dorsum is dark brown with faint transverse bars on the forearms and feet; the ventral surfaces are creamy brown. Trueb and Duellman (1970) provided conclusive evidence that the types of _H. verrucigera_, _riopastazae_, and _orcesi_ are a juvenile, adult female, and adult male, respectively, of one species, the earliest available name for which is _Hyla verrucigera_ Werner, 1901. _Diagnosis._--1) Size moderate, sexual dimorphism evident; maximum observed snout-vent length in males 54.3 mm, in females 65.8 mm; 2) skin on dorsum in males bearing large, keratinized tubercles; 3) skin on flanks smooth; 4) web extending to base of antepenultimate phalange on inner edge of third finger; 5) dorsum uniformly dark brown or black, with tan snout in females; 6) venter creamy white, heavily mottled with black or dark brown, especially in females; 7) lips marked with pale tan labial stripe and suborbital bar; 8) flanks dull reddish brown; 9) dermal roofing bones of skull lacking exostosis; 10) dermal sphenethmoid absent; 11) nasals widely separated medially; 12) anteromedial margin of frontoparietals at anterior border of orbit; 13) frontoparietal fontanelle covered; 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 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 forming simple, tubular, posterolateral extension; associated skin unmodified. _Osteocephalus verrucigerus_ can be distinguished from other members of the genus by its uniformly dark dorsum, heavily mottled venter, and large, spinous tubercles on the dorsum in males. _Distribution._--Lower Amazonian slopes (500-1840 m) of the Andes and on the western fringe of the Amazon Basin in Ecuador and Perú; one locality (Acevedo) in upper Río Magdalena drainage in Colombia (Fig. 9). 40 specimens from 13 localities. _Remarks._--In life the dorsum in males is dull olive-green; the groin, anterior and posterior surfaces of the thighs, inner surfaces of limbs, and upper arms are dark brown. The ventral surfaces of the limbs are pinkish tan; the other ventral surfaces are pale creamy tan with reddish brown spots. The suborbital spot is pale greenish tan, and the iris is deep reddish brown. In females the dorsum is dull olive-brown; the anterior part 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 ventral surfaces of the limbs are brown; the throat and chest are creamy white, and the belly is reddish tan, both with dark brown mottling. Considerable ontogenetic change occurs in coloration. Juveniles are pale above with a dark median dorsal blotch and dark transverse bars on the limbs. The venter is white. The change consists principally of an increase in dark pigment and subsequent obliteration of the juvenile pattern. Tadpoles of this species have moderately long tails with low fins, robust bodies, two rows of labial papillae with median 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 variation in the adults. GENERIC RELATIONSHIPS Among the 33 genera currently recognized in the family Hylidae, there are two basic types of vocal sac structure (Duellman, 1970b), namely the subgular type and the lateral type. Only four hylid genera, all Neotropical lowland groups, are known to possess paired lateral vocal sacs; these are _Osteocephalus_, _Argenteohyla_, _Phrynohyas_, and _Trachycephalus_. The geographical distributions and morphological characteristics of these four genera suggest that they are more closely related to one another than with any other hylid genera. Of the four genera, _Osteocephalus_ is the most generalized in morphology, and, like _Phrynohyas_, has no specialized habits. _Osteocephalus_ and _Argenteohyla_ are similarly distinguished from _Phrynohyas_ and _Trachycephalus_ on the basis of vocal sac structure. The vocal sacs of _Osteocephalus_ and _Argenteohyla_ are posterior and protrude posterolateral to the angles of the jaws when they are inflated, whereas those of _Phrynohyas_ and _Trachycephalus_ are more lateral and protrude posterior to the angles of the jaws when inflated. Although _Osteocephalus_ and _Argenteohyla_ have similar vocal sac structure, they are obviously distinct. The monotypic _Argenteohyla_ is a rather specialized, semifossorial frog (Trueb, 1970b), characterized by smooth skin, moderate-sized digital discs, and a large inner metatarsal tubercle. The general architecture of the skull is not unlike that of _Osteocephalus_; the skulls of both are well roofed, broader than long, and characterized by posterolaterally oriented parasphenoid alae. _Argenteohyla_ bears small, slightly curved prevomerine dentigerous processes in contrast to the large, angular processes of _Osteocephalus_. The skull of _Argenteohyla_ shows specializations, apparently adaptations to its semifossorial mode of existence, which further distinguish the genus from _Osteocephalus_. In comparison with _Osteocephalus_, the cranium of _Argenteohyla_ is slightly depressed anteriorly, the roofing bones extensively casqued, and the palatines robust. Osteologically, _Osteocephalus_ more closely resembles _Phrynohyas_ than either of the other two genera, but _Osteocephalus_ and _Phrynohyas_ are clearly distinct on the basis of their respective vocal sac structure. Like _Osteocephalus_, skulls of the members of the genus _Phrynohyas_ are broader than long, have extensive dermal roofing bones, and have posterolaterally oriented parasphenoid alae. In contrast to _Osteocephalus_, the dentigerous processes of the prevomers are curved, rather than angular in _Phrynohyas_. Furthermore, the latter genus is singularly distinguished from _Osteocephalus_, _Argenteohyla_, and _Trachycephalus_ by having extensively developed parotoid glands that produce a viscous, milky volatile secretion. _Trachycephalus_ is the most readily identifiable of the four genera under discussion. Members of this genus are large frogs with heavily casqued and co-ossified skulls (Trueb, 1970a). The dermal roofing bones bear ornate and characteristic patterns of sculpturing. The medial ramus of the pterygoid does not articulate with the otic capsule, and the parasphenoid alae are laterally, rather than posterolaterally, oriented. A dermal sphenethmoid is present, and the parasphenoid bears odontoids. The basic structure of the skull has many characters in common with both _Osteocephalus_ and _Phrynohyas_. The obvious modifications of dermal roofing bones and of palatal and suspensory elements seem to be specializations adapting members of the genus _Trachycephalus_ to their peculiar phragmotic habits. The vocal sac structure of _Trachycephalus_ is like that of _Phrynohyas_ and therefore further distinguishes it from _Osteocephalus_. Morphologically, _Osteocephalus_ seems to be sufficiently diverse and generalized so as to represent a modern derivative of an ancestral type which might have given rise to _Phrynohyas_, _Trachycephalus_, and _Argenteohyla_. The specialized vocal sac structure in _Phrynohyas_ and _Trachycephalus_ suggests that these two genera may be rather closely allied and represent a single phyletic line from an ancestral stock similar to _Osteocephalus_. _Argenteohyla_ is quite distinct from _Phrynohyas_ and _Trachycephalus_ and apparently represents a distinct phyletic line from the ancestral stock. OCCURRENCE OF _OSTEOCEPHALUS_ IN AMAZONIAN ECUADOR All of our observations on members of this genus have been made at four localities: 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 its formation by the confluence of the Río Cofanes and Río Chingua, and 4) south slope of the Cordillera del Dué, above the Río Coca, 1150 meters. _Osteocephalus leprieurii_ was found at all four localities, 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 are based on collections of 113 frogs and three lots of tadpoles, as well as observations on calling sites and young. The observations are summarized by species, as follows: _Osteocephalus buckleyi._--No breeding activity was observed. Males were found only at night in March, June, and July. One was perched on a _Heliconia_ leaf in a swamp at Puerto Libre, and two were on bushes in the forest at Santa Cecilia. A gravid female was found on a recently felled tree at Lago Agrio on the night of 12 May 1969. _Osteocephalus leprieurii._--Males were heard calling sporadically at Puerto Libre in July 1968, and at Santa Cecilia in May 1969. A small chorus was found on the night of 12 May 1969 at Lago Agrio, where the frogs were perched on branches of fallen trees over a temporary pool. The call is a soft rattling chuckle. In late April and May many gravid females and males with well-developed nuptial excrescences were obtained from trees as they were felled at Lago Agrio. The reproductive condition of the frogs indicates that they probably breed in May. One individual called nearly every night from a large tree at Puerto Libre between 4-17 July 1968. The tree was felled on the latter date, but no frog was found. Two nights later apparently the same individual called from a bromeliad at a height of about 10 m on a large bamboo adjacent to the felled tree; the frog was collected when the bamboo was cut down. Throughout the rainy months that we have worked in Ecuador (April-August) we have found occasional individuals perched on bushes or low trees at night. Large numbers of adults were observed only during a clearing operation which resulted in the felling of many large trees. Thus, it seems likely that _leprieurii_ is a tree-top inhabitant. A partially digested adult male was removed from the stomach of a _Hemiphractus proboscideus_. At Santa Cecilia many recently metamorphosed young and juveniles were found in June and July 1968. Most of these were on low bushes or herbs in swamp forest at night; some were found in unfolded _Heliconia_ leaves by day, and one was observed on the forest floor by day. Snout-vent lengths of 18 specimens are 12.3-17.0 (mean 15.1) mm. The smaller frogs were recently metamorphosed as evidenced by the melanophore deposits above the vent. The coloration of the young is strikingly different from that of the adults (see account of _O. leprieurii_), so the association of the young and adults was not made until individuals with intermediate patterns were obtained at Lago Agrio in May 1969. Probably juveniles obtained in June and July are the offspring of an April or May breeding. We have been unable to associate tadpoles with this species. _Osteocephalus taurinus._--A small chorus occurred at Lago Agrio on 12 May 1969. Males were calling from the ground adjacent to a small pool amidst recently felled trees. The males were very wary and, when approached, jumped onto limbs and ran up branches; this behavior was noted by Bokermann (1964). The call consists of a series of low-pitched, short notes--like a slow trill--four to six notes per call group. Call groups are repeated two, three, or four times followed by a lapse of several minutes. Although no amplectant pairs were found, several gravid females were collected at Lago Agrio in May, so it can be safely assumed that the species breeds in May. From April through July occasional individuals were observed on bushes and trees at night. During clearing operations at Lago Agrio several individuals were obtained from the tops of trees as they were felled. _Osteocephalus verrucigerus._--Observations were made in a broad, shallow ravine, in which there was a small stream. On 2-4 August 1968, males were observed calling from low bushes and rocks at the edge of a quiet pool in the stream. The call consists of a series of well-pulsed, low-pitched, guttural notes produced at the rate of 5-10 per minute. One amplectant pair was found at the base of a bush adjacent to the pool on 3 August. Another female was found on a branch of a tree 2 m above the ground and 10 m from the stream. Tadpoles of this species were found in the quiet silt-bottomed pool. SPECIMENS EXAMINED The localities for each of the specimens examined are given in the following paragraphs. The arrangement of the data is 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 lacking precise locality data are listed first in the most restricted political unit possible; localities which have not been found on maps or the positions of which are not known to us are given in quotation marks. Where more than one specimen is included under one museum number, the number of specimens is given in parentheses after the museum number. Unless noted otherwise, all specimens are alcoholics. _Osteocephalus buckleyi_ BOLIVIA: _El Beni_: Ivón, BMNH 1967.2070-1. _Santa Cruz_: Buenavista, CM 4333, 4339, UMMZ 66563-5. BRASIL: _Amapá_: No specific locality, WCAB 13284. COLOMBIA: _Amazonas_: Río Guacaya, USNM 152759. _Huila_: Acevedo, Río Suaza, FMNH 69702. _Nariño_: Rumiyacu, FMNH 54756. _Meta_: Río Guejar, Campamento La Macarena, USNM 152199. ECUADOR: No specific locality, 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. PERÚ: _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 locality, NHMW 6208. _Osteocephalus leprieurii_ 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 locality, 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 locality, 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. PERÚ: _Loreto_: Estirón, Río Ampiyacu, MZUSP 31033-4; Pebas, CAS-SU 3158, 3160; Roaboya, AMNH 43064. SURINAM: No specific locality, MCZ 2036, RMNH 11468. _Marowijne_: Camp 3, RMNH 13045-6; Wane Creek North, RMNH 11469-70. _Saramacca_: Right Coppename River, RMNH 11467. _Osteocephalus pearsoni_ BOLIVIA: _El Beni_: upper Río Beni, below mouth of Río Mapiri, MCZ 15565, UMMZ 57548, 67464-5; Rurrenbaque, UMMZ 57533. PERÚ: _Pasco_: Yaupi, KU 136312. _Osteocephalus taurinus_ 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 locality: "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 locality, 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 locality, 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 locality, 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; 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 locality: 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. PERÚ: _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 Brasilian frontier, 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 locality, 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. _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. _Osteocephalus verrucigerus_ COLOMBIA: _Huila_: Acevedo, Río Suaza, FMNH 69709-10. ECUADOR: No specific locality, ZMB 16589. _Napo_: Avila, UMMZ 90413; south slope Cordillera del Dué, KU 123176-88, 123189 (skeleton), 124208 (eggs), 124209-11 (tadpoles); L'Alegria, USNM 167472-3; Río Pacayacu, tributary of Río Cotapino, CAS-SU 13150; southeast slope 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. PERÚ: _Ayacucho_: La Mar, Sivia, Río Apurimac, FMNH 39853. _Huanuco_: Río Pachitea, midway between Puerto Victoria and Puerto Inca, CAS-SU 17745. _Junín_: Satipo, MJP 38. LITERATURE CITED ANDERSSON, L. G. 1945. Batrachians from east Ecuador collected 1937, 1938 by Win. Clarke-MacIntyre and Rolf Blomberg. Arkiv Zool., 37A(2):1-88. BOKERMANN, W. C. A. 1964. Field observations on the hylid frog _Osteocephalus taurinus_ Fitz. Herpetologica, 20:252-255. 1966. Lista anotada das localidades tipo de anfíbios Brasileiros. São Paulo, 183 pp. BOULENGER, G. A. 1882. Catalogue of the Batrachia Salientia s. Ecaudata in the collection of the British Museum, ed. 2, London, xvi+503 pp. COCHRAN, D. M. and C. J. GOIN 1970. Frogs of Colombia. Bull. U.S. Natl. Mus., 288:xii+655 pp. COPE, E. D. 1867. On the families of the raniform Anura. Jour. Acad. Nat. Sci. Philadelphia, 2:189-206. 1874. On some Batrachia and Nematognathi brought from the upper Amazon by Prof. Orton. Proc. Acad. Nat. Sci. Philadelphia, 25:120-137. DUELLMAN, W. E. 1970a. Identity of the South American hylid frog _Garbeana garbei_. Copeia, (3):534-538. 1970b. The hylid frogs of Middle America. Monog. Mus. Nat. Hist., Univ. Kansas, 1:xi+753 pp. DUMÉRIL, A. M. C. and G. BIBRON 1841. Erpétologie générale ou histoire naturelle compléte des reptiles, vol. 8. Paris, 792 pp. FITZINGER, L. 1843. Systema reptilium. Vienna, ix+106 pp. FUNKHOUSER, J. 1956. New frogs from Ecuador and southwestern Colombia. Zoologica, 91:73-80. GAIGE, H. T. 1929. Three new tree-frogs from Panama and Bolivia. Occas. Papers Mus. Zool. Univ. Michigan, 207:1-6. GOIN, C. J. 1961. Synopsis of the genera of hylid frogs. Ann. Carnegie Mus., 36:5-18. MELIN, D. 1941. Contribution to the knowledge of Amphibia of South America. Göteborgs Kungl. Vetensk.-och Vitterh.-Sam. Handl., Ser. B, 1(4):1-71. PERACCA, M. G. 1904. Viaggio del Dr. Enrico Festa nell' Ecuador e regioni vicine. Reptile ed amfibii. Boll. Mus. Zool. Anat. Comp., Univ. Torino, 19:1-41. STEINDACHNER, F. 1862. Über zwei noch unbeschriebene Batrachier. Arch. Zool. Anat. Fisiol., 2:77-82. 1867. Amphibien. Novara Expedition. Zool. Theil, I, Vienna, 70 pp. TRUEB, L. 1970a. The evolutionary relationships of casque-headed treefrogs with co-ossified skulls (family Hylidae). Univ. Kansas Publ. Mus. Nat. Hist., 18:547-716. 1970b. The generic status of _Hyla siemersi_ Mertens. Herpetologica, 26:254-267. TRUEB, L. and W. E. DUELLMAN 1970. The systematic status and life history of _Hyla verrucigera_ Werner. Copeia (4):601-610. TYLER, M. 1971. The phylogenetic significance of vocal sac structure in hylid frogs. Univ. Kansas Publ. Mus. Nat. Hist., 19:319-360. WERNER, F. 1901. Ueber Reptilien und Batrachier aus Ecuador und Neu-Guinea. Verh. Zool.-Bot. Gesell. Wien, 50:593-614. UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY The University of Kansas Publications, Museum of Natural History, beginning with volume 1 in 1946, was discontinued with volume 20 in 1971. Shorter research papers formerly published in the above series are now published as Occasional Papers, Museum of Natural History. The Miscellaneous Publications, Museum of Natural History, began with number 1 in 1946. Longer research papers are published in that series. Monographs of the Museum of Natural History were initiated in 1970. Institutional libraries interested in exchanging publications may obtain the Occasional Papers and Miscellaneous Publications by addressing the Exchange Librarian, University of Kansas Library, Lawrence, Kansas 66044. Individuals may purchase separate numbers of all series. Prices may be obtained upon request addressed to Publications Secretary, Museum of Natural History, University of Kansas, Lawrence, Kansas 66044. Transcriber's Notes Except for the list of corrections below and minor corrections not listed, the text presented here is that of the original printed version. Typographical Corrections Page Correction ==== ================ 5 is => in 5 buckley => buckleyi 17 scaral => sacral 19 Provicia => Provincia 25 in => is 25 metalic => metallic 41 bromeiad => bromeliad Text Emphasis _Text_ - Italics =Text= - Bold *** END OF THE PROJECT GUTENBERG EBOOK A SYNOPSIS OF NEOTROPICAL HYLID FROGS, GENUS OSTEOCEPHALUS *** Updated editions will replace the previous one—the old editions will be renamed. Creating the works from print editions not protected by U.S. copyright law means that no one owns a United States copyright in these works, so the Foundation (and you!) can copy and distribute it in the United States without permission and without paying copyright royalties. Special rules, set forth in the General Terms of Use part of this license, apply to copying and distributing Project Gutenberg™ electronic works to protect the PROJECT GUTENBERG™ concept and trademark. 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