340 CLASSIFICATION OF PISHES_, ETC. 



or four ; tail compressed^ permanent ; branchia external^ 

 permanent j lungs rudimentary. 



Proteus Laur. Anterior feet -with three toes ; pos- 

 terior with two only_, and all the legs very small; 

 tail vertically compressed, the edges fin-like ; muzzle 

 lengthened and depressed; eyes excessively small, 

 nearly concealed by the common skin. 

 P, anguinus. Laur. pi. 4. fig. 4. 



SiREDON Wag!., Axolet. Anterior feet with four, pos- 

 terior with five, toes ; resembles in many respects the 

 larva of an aquatic salamander. 



S. pisciformis. Gen. Zool. iii. pi. 140. 



Menobraxchus Harlan. Each of the feet with four 

 toes. 



M. lateralis Harl. 



Siren Linn. Body anguilliform ; no hind feet ; mouth 

 small ; eyes minute ; ears concealed ; teeth only in 

 the lower jaw ; anterior feet small, with four toes ; 

 tail compressed. 



S. lacertina Linn. 



PseudobrancJius Gray. General structure of Siren, but 

 with three toes only on the anterior feet. 



P. striata Gray. (Siren striata Leconte.^ 



Order II. ANOURA. 



Body short and broad ; metamorphous ; complete ; larva 

 or tadpole without feet, but with a compressed tail and 

 external branchia ; the perfect or adult animal with 

 four feet, no tail, and internal branchia. 



Rana Linn. Terrestrial Frogs. All the toes simple, 

 neither dilated at their extremities, or furnished with 

 nails ; mouth toothed ; feet, especially the hinder, 

 very long ; skin smooth ; tongue and tympanum dis- 

 tinct. 



R. esculenta Linn. The common frog. 



