GEOGRAPHICAL DISTRIBUTION. 33 



East Indian islands. They are wholly missing from Australia and are conspicuously 

 restricted in Africa. Only z species occur in the latter continent, and it is possible 

 that one of these was introduced by man, since it inhabits also the south of Europe. 

 Additional remarks on the distribution of the family will be found under the head 

 of Emydidae, on a subsequent page. Unless the genus Gyremys belongs really to 

 the Emydidae, the known members of the family appeared at about the same time 



Fig. 13. Map showing geographical distribution of the Emydidae. 



in America and Europe, in the Lower Eocene. It is remarkable that no members of 

 the group were able to find their way into Africa with the Testudinida?, for the latter 

 were establisht there by the time of the Upper Eocene. 



The Emydidae that occur in South America are all, without doubt, descendants 

 of those that entered that continent at a rather late period from North America. 

 This was probably during the Pliocene. Only 4 species are known. Of these 1 

 belongs to Trachemys, represented by several species in North America, and 3 to 

 Nicoria, a genus occurring also in eastern and southern Asia. Nicoria, however, 



FlG. 14. Map showing geographical distribution of the Testudinidae. 



does not appear to be greatly different from Echmatemys of the Bridger beds, yet 

 distinct; and it is wholly probable that both Asia and South America received their 

 stock from our own country. The distribution of these turtles resembles that of the 

 tapirs. North America possesses at least 25 species of Emydidae. 



In fig. 14. we have a map representing the distribution of the Testudinidae, at 

 present, or at least within historic times. It will be observed that North America, 

 which during the Tertian- was probably everywhere, except in the coldest parts, 



