99- 



The Reptiles of the Awe. 



("December, 



The Emydidce abound in the Eocene beds, and continue in 

 greatly reduced numbers through the Miocene to the present 

 time. But two genera occur in the Eocenes, Dermatemys and 

 Einys, and these still exist. Dermatemys is known by two species, 

 one from the Wasatch, and one from the Bridger (Fig. 9), and by 

 two or three living species from Mexico and Central America. 

 These tortoises have the general appearance of the Baence, in 

 their narrowed sternal lob.es, but they lack the essential characters 

 of that genus, except the intermarginal row of scuta on the sides 

 of the plastron. There are many species of Etnys in all the 

 Eocene beds. They are all nearly smooth, and of medium size, 

 Fig. 10 represents one of them from the Wasatch bed of New 

 Mexico. Its bones are light and thin ; those of E. shaugnessiana 

 Cope, are very thick. The surface of E. septaria Cope, from the 

 Washakie basin, has delicate radiating lines. 



A number of elegantly sculptured species, some of which are 

 of small size, occur in the lacustrine Eocenes. They belong to 

 the genus Plastomenus Cope, and they are not yet sufficiently well 

 known to make it clear whether they are Emydidce or not. 



One genus of Testadinidee ranges through our Eocenes. This 

 is Hadrianus Cope, which only differs from Testudo in having two 

 anal scuta instead of one, so far as the carapace is concerned. 

 There are, perhaps, three species, two of which, H. corsoni and 

 H. oclonarius, grow to a large size (Fig. 1 1-13). They were heavy 

 animals, and represent the earliest of the huge land tortoises of 

 the genus Testudo, which still people the Gallapagos and Mas- 

 carene islands of the Pacific < 



