THE DIFFERENCES BETWEEN THE GEO- 

 GRAPHIC TURTLES (Malacodemmys geo- 

 graphicus and M. lesueuri). 



PLATE II. 



BY H. CARMAN. 



EARLY writers on our herpetology were not fortunate in 

 their treatment of these turtles. Some did not recognize 

 them as distinct, others considered them varieties of one 

 species, while those who admitted their distinctness gener- 

 ally failed to make clear the differences between them. 

 Most recent authors seem to have made use of characters 

 furnished by early writers, and the result is that we have 

 few descriptions which by themselves will enable us to say 

 positively whether examples which come to our hands rep- 

 resent M. lesueuri, or its relative, M. geographicus. 



The original description of M. geographicus (Le Sueur, 

 Journ. Acad. Nat. Sci. Phil., i, 86, 1818) gives no char- 

 acters by means of which this species can be distinguished 

 from the later- described M . lesueuri. But in the accom- 

 panying figure (ibid. pi. v), Le Sueur shows the charac- 

 teristic large head, massive jaw and a peculiar tympanal 

 stripe. After publishing this description, Le Sueur be- 

 came acquainted with M. lesueuri, and the elder Le Conte, 

 writing some time later, stated that he seemed to consider 

 it the one he had described as Testudo geographica. How- 

 ever this may have been, his figure in the Journal of the 

 Philadelphia Academy will not permit us to believe that 

 Le Sueur had anything in mind but M. geographicus when 

 (70) 



