"f t- 



Observations on the Chelonians 



of North America. X. 



DR. R. W. SHUFELDT, C. M. Z. S. 





Diamond-back Terrapin 



Malacoclemmys palustris 



Various classifiers of our terrapins 

 have associated in the genus Mala- 

 coclemmys a number of species to be 

 found in this country, which structur- 

 ally, in several instances, have very little 

 to do with each other. In the present 

 series of articles, Lesueur's Terrapin 

 (M. lesueurii) has already been figured 

 and briefly described. In habits, distri- 

 bution, and in its anatomy, this species 

 is entirely different from the subject of 

 the present account, which is the widely 

 known Diamond-back Terrapin (M. 

 palustris). This is likewise more or less 

 true of the other representatives of the 

 genus, as the Geographic Terrapin (M. 



geographica) ; the Kohn's Terrapin 

 (M. kohnii) ; Baur's Terrapin (M. 

 pulchra), and the Ocellated Terrapin 

 (M. oculifera). 



It is not my intention to present any 

 of these differences in this article, apart 

 from the fact that the Diamond-back is 

 the species which, in its morphology, dis- 

 tribution and habits, departs more widely 

 from what various herpetologists have 

 given as the generic distinctions with 

 respect to other groups of terrapins. 



It would seem that the Diamond-back 

 has been so named for the reason that it 

 has nothing on its back that in any way 

 resembles a diamond. The usual thir- 



