80 CLASS REPTILIA. 



Genus II. Stekkoth^kus, Bell. Breastplate having but 

 one moveable valve, formed of the anterior lobe. The mid- 

 dle and posterior lobes immoveably connected and fixed. 



The species are, 1. Trifasciatus. 2. Leachianus. 3. 

 Odoratus. 4, Boscii. 



Genus III. Terbapene, Merrem. Cistuda, Say. Ster- 

 num bivalve ; the two valves moving on the same anxis ; the 

 posterior valve consisting of the two posterior portions or 

 lobes of the sternum. 



The species are, 1. EuropcBa. 2. Carolina. 3. Maculata. 

 4. Nehulosa. 



The Emydes, whose long tail and voluminous limbs can- 

 not be concealed within the carapace, have given rise to the 

 establishment of a new genus, by M. Schweigger, called Che- 

 lydra. They are separated by our author from the pre- 

 ceding, without any given denomination. 



The first and best known of these is Emys Serpentina, 

 mentioned in the text. The carapace is depressed, oval, and 

 almost subquadrangular, truncated, and a little more narrow 

 in front. The dorsal plates are thirteen, and the marginal 

 five and twenty. All the plates of the carapace are slender, 

 rather transparent, and of a brown colour more or less deep. 



The plastron is small, and has but nine or ten plates, which 

 are smooth and slender. 



The beak is not unlike that of a buzzard, and is terminated 

 by two wattles. The upper jaw is wider than the lower. 

 The neck is at least as long as the body, and very retractile. 

 The upper part of the tail is armed with a denticulated 

 crest. It is as long as the body. This arrangement has 

 occasioned this animal to be named, in Carolina, the alligator 

 tortoise. 



This Emys is found in the fresh waters of North America. 

 It is rare, and much in estimation for the excellence of its 

 flesh. It attains the length of about four feet, and often 



