HERPETOLOGY OF .TAPAX. 



493 



which is not constant, as shown later on. Nor does it appear to be 

 very closelj^ alhed to any of the other species of Clemmys known with 

 certainty to occur on the Chinese mainland, viz, C. healii and C. 

 nigricans. Its nearest relative seems to be C. schmackeri, described 

 not long ago by Doctor Boettger from a young specimen, the locality 

 of which is given as ''China, probabl}' Hainan." It is permissible to 

 suggest that this species may occur in various parts of southern China, 

 and that the unconnected position of C. japonica, so curious in view 

 of the close relationship of the other two Japanese turtles, Amyda 

 japonica and Geoclemys reevesii, may be more apparent than real. 



Clemmys japonica^ and Ocadia siiieiisis are very easily told apart b}^ 

 color alone as indicated in the "key" above (p. 189), but in general 

 proportions, relations of shields, etc., they show many similarities, 



383 



Figs. 382-383.— Clemmys japonic.^.. Jnat. size. 382, carapace; 383, plastron. No. 23522, U.S.N.M. 



although a more close examination of details will reveal a great num- 

 ber of important differences. Apart from the difference in the trit- 

 urating surface of the upper jaw, with a longitudinal ridge in the 

 latter and without one in the former, C. japonica has no median notch 

 to the edge of the upper jaw; its shell is more depressed and the hind 

 lobe of the plastron relatively broader; the posterior outline of the 

 carapace is also strongl}^ serrated. 



Description (figs. 382-383). — Female, third year; U.S.N.M., No. 

 34066; Tokyo; February 23, 1904; A. Owston collection. Snout 

 but slightly projecting, vertical profile slightly oblique, straight; 

 edges of jaws not denticidated, upper jaw without hooks or median 

 notch; triturating surface of upper jaw narrow without any longi- 

 tudinal ridge; mandibular symphysis nearly equaling length of eye 

 slit; skin on entire top of head smooth; body rather depressed, the 



