6. CHRYSEMYS.—7. OCADIA. 85 
United States, east of Ohio, from New York and New Jersey to 
North Carolina. 
a. Hgr., spir. Washington, D.C. Smithsonian Instit. 
b-d. Yg., spir. N. America. Lord Ampthill [ P.}. 
659: 3,2, & ye. N. America. 
stitd. 
h,i,k. 3 2, skel. N. America. 
i. Shell. N. America, (Type of Emys rivulata.) 
12. Chrysemys mobiliensis. 
KEmys mobilensis, Holbr, N. Am. Herp. i. p. 71, pl. ix. (1842) ; Gray, 
Cat. Tort. p. 25 (1844); A. Dum. Cat. Méh. p. 11 (1851). 
Ptychemys mobiliensis, Agassiz, Contr. N. H. U.S. i. p. 433, pl. iii. 
figs. 14-16 (1857). 
Clemmys mobilensis, Strauch, Chelon. Stud. p. 32 (1862). 
Pseudemys mobiliensis, Gray, Ann. § Mag. N. H. (8) xii. p. 182 
(1863), 
Distinguished from C. concinna and C. rubriventris, to which it is 
closely allied, by the greater elevation of the shell anteriorly ; from 
the former by haying the beak notched and bicuspid as in the latter, 
from which it differs by having the upper jaw but very finely 
serrated. 
Borders of the Gulf of Mexico, from Florida to North Mexico. 
7. OCADIA. 
Emys, part., Gray, Cat. Tort. p. 14 (1844), and Sh. Rept.i. p. 19 
(1855) ; Giinth. Rept. Brit. Ind. p. 21 (1864). 
Clemmys, part., Strauch, Chelon. Stud. p. 28 (1862). 
Ocadia, Gray, Suppl. Cat. Sh. Rept. 1. p. 35 (1870). 
Neural plates hexagonal, sh ort-sided in front. Plastron exten- 
sively united to the carapace by suture, with strong axillary and 
inguinal buttresses, extending to halfway between the marginal and 
neural plates, the latter anchylosed between the fifth and sixth 
costal plates ; entoplastron intersected by the humero-pectoral suture. 
Skull with a bony temporal arch; alveolar surfaces broad, of upper 
jaw with a median ridge; choane between the eyes. Upper surface 
of head covered with undivided skin. Digits entirely webbed. 
Tail moderate. 
China. 
1. Ocadia sinensis. 
Emys sinensis, Gray, Proc. Zool. Soc. 1834, p. 53, and Cat. Tort. 
p. 17 (1844), and Sh. Rept. i. p. 20, pl. vii. (1855) ; Grinth. Rept. 
Brit. Ind. p. 27 (1864). 
bennettii, Gray, Cat. Tort. p. 21, and Sh. Rept. i. p. 22, pl. x. 
Clemmys sinensis, Strauch, Chelon. Stud. p. 52 (1862). 
bennettii, Strauch, l. c., and Verth. Schildkr. p. 72 (1865). 
Ocadia sinensis, Gray, Suppl. Cat, Sh. Rept. 1. p. 85 (1870). 
HQ 
