REPTILES. 47 



thigh : a smaller one at the corner of the mouth ; the posterior surface of the 

 hinder legs and the flanks marked with black spots. Iris gold coloured ; tym- 

 panum brown." 



DIMENSIONS. 



In. Lin. 



Length of the head and body 1 8 



of the anterior extremities 1 



of the posterior extremities 2 8 



The young of this species, instead of the bright green colour of the 

 upper parts, is of a delicate grey with small brown markings ; and a lateral 

 fascia of brown, bordered above and beneath with a white line, extends from the 

 fore part of the head backwards, the upper white line nearly to the thigh, the 

 inferior one to the shoulder. The black spots on the flanks and thighs are but 

 just visible. 



This species so nearly resembles the Hyla pulchella of Mons. Bibron, at 

 least as far as his description enables me to ascertain its characters, that it was 

 with some hesitation that I came to the conclusion that they are distinct. 

 Exclusive, however, of the difference of colour, the back of the present species 

 is granulated, and the throat still more distinctly so, whereas the other animal 

 has the skin on the upper parts, as well as on the anterior part of the throat, 

 quite smooth. The palatine teeth also appear to be somewhat differently 

 arranged. 



Mr. Darwin observes, that this species was found in numbers in the open 

 grass plains, and likewise in swamps, about Maldonado, and that they can 

 never ascend trees, as these are entirely wanting at the places frequented by 

 the Hylae. 



Fam.— BUFONIDtE. 



Genus— RHINODERMA. Bibr. 



Lingua cordato-ovata, postice libera et subemarginata. Dentes palatini nulli. Tym- 

 panum celatum. Glandae parotides nullcE. Digiti breves, depressi; anteriores 

 ad basin tantum, posteriores fere dimidio palmati. Rostrum cutis appendiculo 

 jiliformi instructum. 



