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Show 40 ZOOLOGY OF TilE VOYAGE OF TilE DEAGLE. 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. Cotoun.- 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 RANIDJE, of the absence of palatine teeth ; the others being Oxyglossus Lima of Tschudi, and Leiuperus 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 tho head and body ....... 00 .... ... .... 00.... 0 of the anterior extremities .. .. 00 •• • 00 .. 00 . 00 00. 0 of the posterior extremities .... 00 . .. . ..... 00 .. 00 1 I It was found by Mr. Darwin at Port Desire, and its habitat is very remarkable. " It is bred in and inhabits water far too salt to drink." GENus-PYXICEPHALUS. Bibr. PYXICEPHALUS AMERICANUS. Bibr. PLATE XVIII.-Fig. 2. Lingud cordiformi; dentibus palatinis in lined transtiersa inte1·rupta, inter nare1 posteriores positis; tympano celato; dorso mamrnillato. 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 41 ~y Mons. d'Orbi?~Y· and which formed the subject of Mons. Bibron's descri - tJOn. Mr. Darwm s specimen was taken on the open plains at Monte Video p . ~f the three species of this remarkable genus at present known tw~ are Inhabitants of Africa, from ·whence they were brought by Delalande. As neither of ~hem has as yet been figured, it was thought desirable that the present opportumty should be taken to exhibit some of the generic characters and especially the hard horny spur on the hinder foot. ' REPTILES. This genus is one of those bufonine forms of the RANID.IE which irresistibly lead us to ~o~bt the correctness of the present received arrangement of the anourous Amphibia, GENus-ALSODES. Bell. Caput c_o~ve_xum. Lingua antice acute-producta, postice rotundata, et libera. Dentes palatim ~nter nares posteriores. Tympanum celatum. Aperturre Eustachianre ltaud conspi.cua. Digiti anteriores ad basin tantum-posteriores usque ad pltalangem tertzum membrana connexi. A. genus of the Rani form group, nearly allied, as Mons. Bibron observes, to Scal!lnopus, by the structure of the hands, which, although without any projecting r~1d1mentary thumb, has a small process under the skin, along the extreme margm 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. Milti. PLATE XVIII.-Fm. 8. DESCIUPTION.-!Iead 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 G |