50 EMYSFLORIDANA. 



I. They differ so much in colour and markings, as may be seen in the accom- 

 panying plates, that this of itself would be almost sufficient to distinguish them in 

 the living animals. 



II. They differ greatly in size. 



III. In geographical distribution. 



IV. In the various characters of the head, jaws, and shell, as heretofore described. 



The Emys serrata has the jaws without serrse, the upper slightly emarginate 

 in front, the posterior margin of the shell deeply serrate; inhabits the Caroiinas. 



The Emys rubriventris approaches nearest to it, but has the upper jaw so deeply 

 emarginate in front as to present the appearance of two teeth; and the lower 

 deeply serrated, and toothed in front; inhabits from Western Jersey to Virginia; 

 these two animals are nearly of the same size. 



The Emys reticulata is widely different; it has the upper jaw emarginate in 

 front; lower one hooked; shell perfectly entire; inhabits the Caroiinas. 



The Emys floridana comes nearest the Emys reticulata, in its characters, but is 

 still perfectly distinct; the upper and lower jaws are both entire, without hook or 

 serrse; shell entire. This animal is six or eight times the size of the reticulata; 

 inhabits East Florida. 



The Emys scripta, if a North American tortoise, is the young of the Emys 

 serrata. 



The Emys decussata (Bell and Gray*) has not been found in the United States, 



* Gray Synop. Rept, p. 28, spec. xxii. 



