40 
ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 
panum not very conspicuous ; there is a trace of a parotid gland on each side of the neck. The 
body is rather thick, and the limbs proportionally short. The hinder toes are only connected 
at the base by a rudimentary membrane, the first four gradually increasing in length, and 
placed along the side of the matatarsus, one beyond the other ; the fifth on the same line as 
the fourth, but not more than half its length. The metatarsal tubercle is rather prominent, 
and there are small subarticular tubercles on the toes of all the feet. 
Colour. — The colour of the upper parts is brownish black. On each side near the thigh are three 
or four perfectly round black spots, each surrounded with a white line. The under parts 
whitish. 
Of this second species of a rare and remarkable genus, one specimen only 
exists in Mr. Darwin’s collection. It is only the third known instance, in the 
family of the Ranid^, of the absence of palatine teeth ; the others being 
Oxyglossus Lima of Tschudi, and Leiwperus marmoratus of Bibron. The present 
genus must be considered as nearly approaching the family of the BufonidjE in 
the absence of palatine and the extreme minuteness of the maxillary teeth, in 
the extremely small gape of the mouth, the thick form of the body, the shortness 
of the limbs, and the existence of rudimentary parotid glands. I have not had 
an opportunity of comparing this specimen with those on which Bibron founded 
the genus, but I cannot doubt the specific distinction between them. 
DIMENSIONS. 
In. Lin. 
Length of the head and body 0 9 
of the anterior extremities 0 5 
of the posterior extremities 1 1 
It was found by Mr. Darwin at Port Desire, and its habitat is very remark- 
able. “ It is bred in and inhabits water far too salt to drink.” 
Genus— PYXICEPHALUS. Bibr. 
Pyxicephalus Americanus. Bibr. 
Plate XYHL— Fig. 2. 
Lingua cordiformi ; dentibus palatinis in lined transversd interrupta, inter nares 
posleriores positis ; tympana celato ; dorso mamniillato. 
This curious species has, I believe, only once before been found. A single 
specimen exists in the French Museum, which was brought from Buenos Ayres 
