10 NEW-YORK FAUNA. 



GENUS EMYS. Brongniart. 



Shell not much elevated, solid, covered with horny plates. Sternum solid, broad, immovable ; 

 of six pair and four supplemental plates. Feet palmate ; anterior with five claws, posterior 

 with four. 



This genus comprises nearly all the fresh water tortoises discovered in America. In this 

 State, we enumerate nine species. 



THE SALT-WATER TERRAPIN. 



EmyS PALnSTRIS. 



PLATE III. FIG. 5. — (STATE COLLECTION.) 



Testudo palustns. LiN. Gmel. 



Tortus a Ugnfs concerUriqius. Daud. Hist. Nat. Rep. Vol. 2, p. 153. 



JEmys centrata. Say, Acad. Sc. Nat. Philad. Vol. 4, p. 211. Harl. Med. and Phys. p. 153. 



T. palustns. Le Conte, Annals of the Lye. Nat. Hist. Vol. 3, p. 113. 



Characteristics. Shell oval, obtusely carinate ; the plates with numerous deeply impressed 

 concentric striae ; the last vertebral plate rounded in front. Beneath, red- 

 dish or orange, dusky, irregular stripes or rings. Length 5-7 inches. 



Description. Shell emarginate behind, depressed, but the extent of this depression varies 

 in different individuals ; occasionally quite elevated, and as if distinctly carinated along the 

 vertebral plates. Each plate is very distinctly marked, particularly in the males, by five to 

 seven or eight regularly concentric lines, parallel with the direction of the sides of the plate : 

 varieties occur, in which the plates are nearly smooth. The first vertebral plate quadrate, the 

 remainder six sided ; the last jjolygonal, the anterior margins forming nearly a curved line. 

 Lateral plates, the three first pentagonal ; the last small, subquadrate. Marginal plates 

 twenty-five, unequal in size ; the intermediate small, oblong, linear, the outer edge occasionally 

 emarginate, sometimes triangular, truncate ; the posterior plates small, somewhat upturned. 

 Sternum of six pair ; the gular plates small, triangular, with impressed concentric angular 

 Unes ; the next pair larger, subquadrate, enlarged on the outer margin ; the three following 

 subequal, the caudal pair rounded behind, where they form a broad emargination. Extre- 

 mities with separate scales. 



Color. Usually of a dull ash brown above, varying in intensity in different individuals, 

 sometimes approaching to black. Beneath, reddish or orange, occasionally pale and dull yel- 

 lowish, with dusky dashes and rings on the sternal plates and lower side of the marginal plates. 

 Head, neck and extremities dull bluish ash, with numerous spots of black. 



Length, 5-0- 7-0. 



Height, 1-0- 2-5. 



