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U.S. NATIONAL MUSEUM BULLETIN 2 88 



G. mertensi can be distinguished from all Colombian Gastrotheca ex- 

 cept helenae, monticola argenteovirens , and aureomaculata by the ab- 

 sence of both superciliary processes and dermal appendages on the 

 heels and by its having the cranial derm free. Its uniform pattern easily 

 distinguishes it from both helenae and aureomaculata. From monticola 

 argenteovirens it differs in its larger size and in the fact that the adults 

 are uniform below rather than mottled. 



Description ojholotype. — Vomerine teeth in two short, heavy, trans- 

 verse series, lying close together between the small, rounded choanae; 

 tongue half as wide as mouth opening, longer than wide, its posterior 

 border free and distinctly notched. Snout large, somewhat elongate 

 and triangular for a Gastrotheca when viewed from above, truncate 

 and slightly sloping in profile, the upper jaw extending but slightly 



Figure 17. — Gastrotheca mertensi, holotype, MZUM 121024 (same size). 



