658 REPTILES — EMYDID^. 



Key to Oenera of Emydid^. 



* Upper jaw notched anteriorly, a. 



* Upper jaw not notched anteriorly, or with only a sinnons indentation. 6. 



a. Carapax not carinate. c. 



a. Carapax carinate. .... .... Chelofus. 



6. Vertebral keel persistent in the adult; lower jaw with\ a spoon- shaped 



dilatation Graptkmys. 



&. Vertebral line in adnlt tubercnlated ; horny sheath of jaws straight ; extra- 



limital. * Malacoclemmys. 



0. Carapax considerably arched, and nsnaily more or lees spotted on the 



vertebral and costal plates, d. 

 e. Carapax depressed ; vertebral and costal plates not spotted, e. 

 d. Plastron without a movable transverse hinge ; costal and vertebral 

 plates with isolated, round, nonconflaent yellow spots. . . . Nanbmys. 



d. Plastron with a movable transverse suture ; vertebral, and usually the 



costal plates, without round yellow spots Emys. 



e. Alveolar surface of jaw not divided by a longitudinal ridge ; neck, legs 



and tail often with bright red stripes Chrysemys. 



6. Alveolar surface of jaw with a ridge parallel to cutting edge ; no scarlet 

 stripes Psetjdkmys. 



Gekus CHELOPUS. Eafinesque. 



Upper jaw with a distinct notch anteriorly; lower jaw straight except at tip, or 

 arched upward ; horizontal alveolar surface narrow ; sides of head compressed ; plastron 

 immovably soldered together and to the carapax ; head compressed laterally ; carapax 

 elongated, considerably arched, and provided with a keel. 



* A dark orange blotch on each side of the neck extending over the temporal muscles j 



extralimital. New York, New Jersey, and Pennsylvania. . t C muhlenbkkgu. 



* Sides of neck without such spots. C. inscclptus. 



Chelopus insculptds LeConte. 



Sculptured Tortoise. 



Ttstudo insculpiiia, LkConte, Haelan. 



Emys scabra, Say. 



Evtys irtseulptus, LbConte, Holbeook, DkKay, Stoker. 



Emye piilchella, Dumeril and Bibron. 



Emys speciosa, Gray. 



Ghjplemys insatlptus, Agassiz, Verrill, Allen. 



Chelopus insculpiuB, Cope, Jobdon. 



" One species Malacocltmmys palueiris {Emys paTuiMe, et terrapin, DeKay), Agassiz's 

 Cont., i, p. 437; Holbiook's N. A. Ileip., i, p. b7 ; DeKay's Kept. N. Y., p. 10, ranges 

 along the Atlantic coast, in salt marshes, from New Yoik to Texas and South America. 



t Agassiz's Cont., i, p. 443 ; Holbrook's N. A. Herp., i, p. 45 ; DeKay's Rept., p. 17. 



