Chap. III. GENERA OF EMYDOIDiE. 441 



SUB-FAMILY OF THE DEIROCHELYOID.E. 



This sub-family embraces only a single genus, as far as I know, and to this 

 day that genus numbers a single species, the North American Emys reticulata, 

 Schti'eig} In many respects it recalls the AuvStralian Chelodinge, by the unusual 

 length of its neck ; but differs strikingly from them by the mode of articula- 

 tion of its neck vertebra?. It is a genuine Cryptodeira, and in no way allied 

 to the Pleurodeira?.^ 



Deirochelys, Ag. The upper jaw is notched in front j the lower jaw is low, 

 arched upwards, and terminates in a sharp point. 



Deirochelys reticulata, Ag. The geographical range of this species is much 

 more extensive than is generally supposed. It is foimd in all the Southern 

 States, from the southern parts of North Carolina to Louisiana, though it seems 

 to be nowhere very common. I have obtained specimens from North Carolina, 

 through Mr. S. Th. Abert and Dr. C. L. Hunter ; from South Carolina, through Dr. 

 Ilolbrook ; from Pensacola, through Dr. E. W. JefFries ; from Mobile, through Dr. 

 Nott ; and from Red Kivei', Louisiana, through Professor Baird. The young are 

 represented PI. I., fig. 14-16, and PL II., fig. 1-3 ; and the eggs, PI. VII., fig. 17-19. 



genera of the sub-f.\mily of evemydoid.e. 



Emys, Brongn? All modern herpetologists, with the exception of Dr. Holbrook 

 and Maj. LeConte, have confomided the North American representative of this 

 genus with the common Box Turtle,* Cistudo virginea, with which it is onlv 

 remotely allied. The distinguishing character of the genus consists in the nar- 

 row, horizontal alveolar surface, and the narrow, horny sheath of the bill, which 

 is notched in front, the alveolar edge rising gradually to form a triangular 

 emargination, while under the eye it is arched down. No part of the plastron 

 is sutured to the carapace ; the median pair of bones are united to it by unos- 

 sified, flexible derm ; the plastron itself is hinged at the middle transverse suture, 

 and the two movable plates, thus hinged upon one another, are raised to the 



' Compare Ilolb. N. Amor. Ilcrp. p. .'iO, pi. 7. served. lie has further subdivided the Cistudos, 



It is the Testudo reticulata, Bosc. ; Tcrrapcre reticu- with which he associates the genus Lutremys, into 



lata, Bonap, Cistudo proper and Cyclemj-s. 



* Compare p. 335, note, and 351. * Diim. ami IJibr. Erp. g^n. vol. 2. p. 210 ; Gray. 



' Gray has proposed the name Lutremys for this Cat. IJrit. INIus. p. 30. Comp. also my remarks, p. 



genus; but the older name, Emys, must bo pre- 249 and 252. 



56 



