48 ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 



Rhinoderma Darwinii. Bibr. 



Plate XX.— Fig. 1, 2. 



Supra pallide rufo-cinereum, fasciis iransversis viridescentibus ; subtus castaneo- 



nigrum, maculis albis. 



Rhinoderma Darwinii. Bibr. Hist. Nat. Rept. VIII. p. 659. Var. Dorso fuscescenti-nigro. 



Description. — The head and body are flattened, the head triangular, slightly truncated in front, 

 but appearing angular from the skin being produced into a small filiform appendage, standing 

 forwards from the extremity of the snout. The eyes are lateral, slightly prominent. Body 

 very slender. Skin perfectly smooth, and without apparent glands, excepting on the thighs. 

 Fore legs rather short, reaching quite to the thighs when placed by the side ; the toes almost 

 wholly separate, there being but the rudiment of a connecting membrane at their base. Hinder 

 legs long, extending forwards beyond the head by the whole length of the foot ; the hinder 

 toes are connected nearly half their length, and the connecting membrane is thick and 

 coloured like the rest of the skin. 



Colour. — The colour varies greatly in different individuals. The following are the principal 

 variations in the specimens collected by Mr. Darwin. Above pale iron rust-colour, with a 

 transverse fascia across the head, a triangular one over the shoulders, a large broad mark on the 

 loins, and the upper part of the thighs all of a bright beautiful green. The under side ante- 

 riorly rich chestnut-brown, passing into black posteriorly, with several irregular snow-white 

 spots, particularly a broad one across the belly, and white bands across the legs. Another 

 specimen was cream colour above, the markings darker, and with small spots of green. In one 

 the chestnut colour beneath was replaced by bright yellow. There is one, constituting a 

 very distinct variety, in which the upper part is wholly and almost uniformly dark brown. 

 The female is greenish grey above, without conspicuous markings. 



This is the only known species of the genus, which was founded by Mons. 

 Bibron upon the specimens collected by Mr. Darwin. The general slightness 

 and elegance of its form, and its slender proportions, would lead us to consider it 

 at first sight as rather belonging to the Ranidce than the Bufonidcp ; but the total 

 absence of teeth in the upper maxillary arch, shews that its proper place is in the 

 latter group. Its form and the length of the posterior extremities would also pre- 

 pare us to expect that it can leap freely, which Mr. Darwin states to be the fact. 

 It inhabits thick and gloomy forests, and is excessively common in the forest of 

 Valdivia. 



DIMENSIONS. 



In. Lin. 



Length of the head and body 1 



of the anterior extremities 5 



of the posterior extremities 1 4 



