CLASS REPTILIA. 



body rather depressed ; tail compressed ; legs four ; muz?le 

 depressed. 



a. Toes 3 before, 2 behind. Hydochthon. 



Common Proteus. Proteus anguinus, Laur. Siren 

 anguinus, Sclm. See Configliachi, Monografra and Schrie- 

 ber's, Monograph, Carniola. 



b. Toes 4 before, 4 behind. Menobranchus, Harlan. Nec- 



turus, Raffin. Phanerobranchus, Fit%. 



Say's Menobranchus. Menobranchus lateralis, Harlan. 

 Triton lateralis. Acad. Nat. Sci. Philad. iv. t. 21. Ann. 

 Lye. N. ij. 1. 16. Proteus of the Lakes, Mitchell, Silliman 



Jour, iv. and vii. Salamandra alleghaniensis, Jun. Say. 



Lacepedes Menobranchus. Menobranchus Lacepedii. 



Proteus tetradactylus. Lacep. Ann. Mus. x. t. 



c. Toes 4 before, 5 behind. Phyllhydrus, Brooks, Gyrinus. 



Shaw not Lin. Siredon, Wagler. 



Common Axolotl. Phyllhydrus pisceformormis. Siren 

 pisciformis. Shaw Zool. iij. t. 140. Misc. t. Axolotl Hum- 

 boldt. Obs. Zool. t. 12. Home Phil. Trans, and Lacep. 

 Anat. Siredon Axolotl, Wagler. Mexico. Consult also 

 Proteus Nove Caesarcenris, Green. Jour Acad. Phil, and 

 Siren operculata, Pal de Beauv. Amer. Phil. Trans, iv. 



Gen. II. Siren. 



Gills free, persistent ; skull of distinct bones : body sub- 

 cylindrical ; tail compressed ; legs two, anterior. 



a. Toes 4, 4. Siren, Linn. Muraena, Gmel. 



Common Siren. Siren lacertina, Linn. Mud Iguana. 



Ellis Phil. Trans. Intermediate Siren. Siren intermedia, 



Leconte Ann. Lye. New York ij. t. 1. 

 108 



