284 U.S. NATIONAL MUSEUM BULLETIN 2 88 



Tolima: Espinal, MCZ 15608; Mariquita, CNHM 81822-3. 

 No precise locality: ANSP 19749. 

 PANAMA: Darien, El Real, USNM 140567-8. 



Hyla riveroi, new species 



Figure 29 

 1958. Hyla misera Goin, p. 120. — Goin and Layne, 1958, p. 104. 



Holotype. — CM 37433, collected at Leticia, Amazonas, Colombia, 

 by E. Ross Allen in 1956. 



Paratypes.—CJG 2331-2, 2335, MZUM 125428-9, UF 8556 (6), 

 8557 (4), CM 36085 (12), USNM 146256-7, all from Leticia, Ama- 

 zonas, Colombia; FM 154 (2), from Quebrada Honda, Sabana de 

 San Juan der Arama, Meta, Colombia; WCAB 1705-8, from Acre, 

 Brazil. 



Diagnosis. — A tiny yellow frog allied to Hyla microcephala. 



The lack of parallel stripes on the back distinguishes Hyla riveroi 

 from H. microcephala; the mottled dorsal pattern and the lack of con- 

 spicuous subdermal lymph sacs in the dorsolateral region distinguish 

 it from H. mathiassoni; and the dorsal pattern of crossbars or blotches 

 rather than an hour glass-shaped figure distinguishes it from H. 

 phlebodes. 



Description of holotype. — Vomerine teeth in two short, rounded series, 

 lying on a level between the small, rounded choanae; tongue three- 

 fourths as wide as mouth opening, broadly rounded, its posterior border 

 free and slightly notched. Snout short, rounded when viewed from 

 above, slightly rounded in profile, the upper jaw extending a little 

 beyond lower; nostrils more lateral than superior, somewhat project- 

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

 separated from each other by an interval equal to about their distance 

 from eye. Can thus rostralis well defined; loreal region concave and 

 nearly vertical, the upper lip flaring out below it only slightly. Eye 

 large, very prominent, its diameter half again as great as its distance 

 from nostril; palpebral membrane not reticulate; interorbital distance 

 slightly greater than width of upper eyelid, which is relatively wide 

 and about equal the distance between nostrils. Tympanum very 

 distinct, about one-fourth the diameter of eye, separated from eye by a 

 distance about equal to one-third its own diameter. Fingers webbed 

 at base, fourth finger considerably longer than second, just reaching 

 to disk of third which covers about three-fourths the tympanic area ; 

 no projecting rudiment of a pollex; no ulnar ridge. Toes slightly more 

 than one-half webbed, web on fourth toe reaching distal end of 

 penultimate phalanx, third and fifth toes subequal, disk of fourth toe 

 covering about one-third the tympanic area ; a distinct oval inner and 



