8 NEW-YORK FAUNA. 



GENUS CHELONURA. Fleming. 



Head large, with small plates. Both jaws strongly hooked Sternum small, cruciform, 

 immovable. Tail long, and furnished with a scaly or tuberculated crest. Anterior feet 

 with five claws ; posterior with four. 



Obs. This genus is identical with the Emysaurus of Dumeril & Bibron, Rapara of Gray, 

 and Saurochelys of Latreille. The Chelydra of Schweigger appears to have been founded 

 on the young of the C. serpentina. I am acquainted with but one species in the United States. 

 Dr. Harlan, in his Medical and Physical Researches, has indicated the existence of another 

 from Tennessee, but has given no detailed description. 



THE SNAPPING TURTLE. 



Chelonura serpentina. 



PLATE III. FIG. 6. Yodnq. 



Testudo serpentina. L. Sysb. p. 354. 



T. id. Daodin, Vol. 2, p. 98, pi. 20, fig, 2. 



Chelonura serpentina. Say, Acad. Nat. Sc. Vol. 4, p. 217. 



Chelydra lacertina. Schweigg. Monog. (Young.) 



Testudo serpentina. Le C. Ann. Lye. Nat. Hist. N. Y. Vol. 3, p. 127. 



Emys (Chelydra) serpentina. Gray, Synopsis Rept. apud Griff. Cuv. Vol. 9, p. 14. 



Chelydra serpentina. Ham.. Med. & Phys. p. 157. 



Emysaurus id. Dcmeril & Bib. Vol. 2, p. 350. 



Emysaurus id. Storer, Mass. Rep. p. 212. 



Chelonura id. Holbrook, Am. Herp. Vol. 4, p. 21, pi. 3; and Vol. 1, p. 139, pi. 23, of the 2d Ed. 



Characteristics. Shell oval, more or less carinate, three-toothed on its posterior margin. Upper 

 jaw hooked, acute. Head long and wide. Snout attenuated. Length 

 2-4 feet. 



Description. Shell oval, little elevated, with a dorsal ridge produced by the elevation of the 

 posterior margin of the vertebral plates. Five vertebral, eight lateral and twenty-five marginal 

 plates. The first lateral plate triangular, with its outer base rounded ; the remainder sub- 

 quadrate, the posterior smallest. The marginal plates small, oblong, and gradually enlarging 

 on the sides ; the posterior largest, and of these, three and occasionally four with strong spi- 

 nous angles. The vertebral plates are quadrate, except the last, which is pentagonal. Sternum 

 composed of ten plates ; the anterior pair small, the two following pair gradually larger. The 

 wing or supplementary plates long and narrow, united to the marginal plates by two small 

 plates ; these wing plates are attached beneath to the pectoral and femoral pair. Caudal 

 plates long, narrow and triangular. Head exceedingly large, scaly above. Skin of the neck 

 loose, and thickly covered above with fleshy warts, somewhat smoother beneath. Jaws stout, 

 the upper jaw largest. Legs robust. Fore feet covered above by series of scales, of which 

 those on the posterior edge are largest. Hind legs with similar large scales beneath. Toes 



