REPTILES. 
41 
by Mons. d’Orbigny, and which formed the subject of Mons. Bibron’s descrip- 
tion. Mr. Darwin’s specimen was taken on the open plains at Monte Video. 
Of the three species of this remarkable genus at present known, two are 
inhabitants of Africa, from whence they were brought by Delalande. As neither 
of them has as yet been figured, it was thought desirable that the present oppor- 
tunity should be taken to exhibit some of the generic characters, and especially 
the hard horny spur on the hinder foot. 
This genus is one of those bufonine forms of the RanidjE which irresistibly 
lead us to doubt the correctness of the present received arrangement of the anou- 
rous Amphibia. 
Genus — ALSODES. Bell. 
Caput convexum. Lingua anticl acute-producta, postich rotundata, et libera. Dentes 
palatini inter nares posteriores. Tympanum celatum. Apertures Eustachianee 
hand conspicucE. Digiti anteriores ad basin tantum — posteriores usque ad plia~ 
langem tertium membrand connexi. 
A genus of the Raniform group, nearly allied, as Mons. Bibron observes, to 
Seaphiopus, by the structure of the hands, which, although without any projecting 
rudimentary thumb, has a small process under the skin, along the extreme mar- 
gin of the first finger. In common with the genus Bombinator, it has the opening 
of the Eustachian tubes so small as scarcely to be detected. 
Alsodes monticola. 3Iihi. 
Plate XVIII.— Fig. 3. 
Description. — Head semi-elliptical, somewhat convex, with the muzzle nearly perpendicular; 
vertex smooth. Eyes of moderate size. Nostrils very small, opening upwards. Tongue 
broad and rounded behind, narrowing to a point at the apex, detached at the posterior part. 
Palatine teeth in two small approximate patches, between the posterior nostrils. Openings of 
the Eustachian tubes scarcely visible. Extremities of moderate length. The fore feet, with 
four rather short toes, connected at the base by a short membrane ; the inner toe broad, and 
with a slight projection under the skin, along its inner margin ; hinder toes connected as far as 
the joint of the second and third phalanges. 
The colour of the only specimen in the collection has become totally changed 
into a smoky brown by the spirit, but the following is Mr. Darwin’s description 
