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U.S. NATIONAL MUSEUM BULLETIN 2 88 



Diagnosis. — A small Hyla of the leucophyllata group with con- 

 spicuous supraocular light spots or interocular bar and without a 

 triangular light area on top of the head. 



H. rossalleni may be distinguished from H. sarayacuensis, its nearest 

 relative, by the presence of the supraocular spots, by having the 

 dorsolateral light stripe broken up into more or less elongate light 

 spots, and by its smaller size. From H. leucophyllata it differs by lacking 

 vomerine teeth and by lacking the large white daub which covers the 

 dorsal surface of the cms. 



Description. — UF 8501 (holotype), from Leticia, Amazonas, Co- 

 lombia. Vomerine teeth absent; choanae moderate in size, rounded, 

 and well separated; tongue nearly round, not notched behind and but 

 slightly free behind, its diameter about two-thirds the width of mouth. 

 Head broad, its width greater than distance from snout to occiput; 

 snout nearly rounded as seen from above; upper jaw very slightly 

 projecting. Eyes large and protuberant; diameter of eye greater than 

 the distance from eye to nostril; nostril very near tip of snout; inter- 

 orbital space about equal to diameter of individual eye. Tympanum 

 distinct but small, not more than one-third the diameter of eye; 



Figure 33. — Hyla rossalleni, UF 8501 (X 2). 



