FROGS OF COLOMBIA — COCHRAN AND GOIN 317 



Genus Osteocephalus Steindachner 



1862. Osteocephalus Steindachner, p. 77 (type species, Osteocephalus taurinus 

 Steindachner). 



Generic diagnosis. — Males with paired vocal pouches; skin on top 

 of head neither thickened nor co-ossified with skull, roof of skull very 

 weakly to markedly exostosed. 



Key to Colombian Species of Osteocephalus 



a 1 . Top of head flattened and moderately to heavily exostosed; canthus rostralis 

 nearly straight. 

 b l . Dorsum with numerous, small, spiny warts giving the back a sandpapery 



effect; top of skull heavily exostosed O. taurinus 



b 2 . Dorsum smooth or slightly roughened but not with pronounced sandpapery 



effect; top of skull moderately exostosed O. Ieprieuri 



a 2 . Top of head rounded and not heavily exostosed; canthus rostralis curved. 



O. orcesi 



Osteocephalus orcesi (Funkhouser) 



Figure 38; Plate 38a-c 



1956. Hyla orcesi Funkhouser, p. 78 (type locality, Ecuador, Napo-Pastaza 

 Province, Suno drainage, tributary of Rio Cotapino, 600 m.)' — Gorham, 

 1963, p. 22. 



Diagnosis. — A small Osteocephalus with numerous spiny warts on 

 the back which give the dorsum a sandpaper-like effect. 



0. orcesi may be distinguished from 0. Ieprieuri by the sandpaper- 

 like back and from 0. taurinus by its smaller size, rounded head, and 

 lack of large exostoses on the skull. 



Description. — CNHM 69710, from Acevedo, Rio Suazo, near San 

 Adolfo, Huila, Colombia. Vomerine teeth in two short, more or less 

 transverse series, lying close together between the moderate, ovate 

 choanae; tongue three-fourths as wide as mouth opening, broadly 

 cordiform, broader than long, its posterior border slightly free and 

 shallowly notched. Snout moderate, rounded when viewed from above, 

 nearly truncate in profile, the upper jow extending very little beyond 

 lower; nostrils more lateral than superior, considerably projecting, 

 their distance from end of snout about one-third that from eye, 

 separated from each other by an interval equal to about two-thirds 

 their distance from eye. Canthus rostralis rather well defined; loreal 

 region concave but not particularly oblique, the upper lip flaring 

 out only slightly below it. Eye moderate, not prominent, its diameter 

 equal to its distance from nostril; palpebral membrane not reticulate; 

 interorbital distance slightly less than width of upper eyelid, which 

 is relatively wide and slightly greater than distance between nostrils. 



