BATRACHIA. 89 



Among those which always retain their branchise, the 



AXOLOTUS 



Is in every respect similar to the larva of-an aquatic Salamander, 

 having four toes before, five behind, three long tufted branchiae, Sec. 

 The maxillary teeth are like velvet, and those on the vomer in two 

 bands. Such is the 



Siren pisciformis, Shaw; the Axolotl of the Mexicans; Gen. 



Zool. vol. Ill, part ii, pi. 140; Humb. Zool. Obs. I, pi. 12. 



From eight to ten inches long; grey, spotted with black. It 



inhabits the lake that surrounds Mexico .(l) 



Menobranchus, Harl. — JVecturus, Raffin. 



But four toes to all the feet; a range of teeth in the intermaxillaries, 

 and another, parallel, but more extended, in the maxillaries. 



The species most known, Menobranchus lateralis, Harl.; Tri- 

 ton lateralis. Say; Ann. of the New York Lye. I, pi. xvi, inha- 

 bits the great lakes of North America, attaining, as it is said, 

 the length of two and three feet. It Avas first obtained from 

 Lake Champlain. 



Proteus^ Laurent. — Hypochton, Merr. 



But three toes before and only two behind. 



Hitherto but a single species has been discovered, Proteus 

 anguinus, Laur. pi. IV, f. 3; Daud., VIII, xcix, 1; Siren an- 

 guina, Schn. More than a foot long, about the thickness of a 

 finger, v/ith a vertically compressed tail and four small legs. 

 Its muzzle is elongated and depressed; its two jaws furnished 

 with teeth; its tongue but slightly movable and free before; its 

 eyes extremely small and hidden by the skin, like those of the 

 Zemni (Mus typhus, Pall.); the ear covered by the muscles as 

 in the Salamanders, and the skin smooth and whitish. It is 

 only found in some subterraneous streams, by which certain 

 lakes in Carniola communicate with each other. The skeleton 

 resembles that of the Salamander, except that it has many more 

 vertebrae, and fewer rudiments of ribs; the bony head, however, 

 differs altogether in its general conformation. 

 Finally, there are some which are possessed of fore feet only, the 



hind ones being entirely deficient. They are 



(1) It is with some hesitation that I place the Axolotl among the genera with 

 permanent branchiae, but so many witnesses assure us that it does not lose tiiem 

 that I am compelled to do so. 

 Vol. II.— M 



