The Fossil Turtles of the Bridget Basin— Hay. 341 
» 
chelonian fauna is therefore poorer in all respects than that 
of the Bridger beds, but much like the latter as far as it 
goes. 
A few words may be added regarding the relations of 
the Bridger turtles to those of North America to-day. From 
materials in the American ]\Iuseum of Natural History it 
is known that the genus Baena continued on until the 
Uinta. After this nothing is known of it. It is certain 
that the genus Baptemys became extinct, leaving no de- 
scendants living to-day. No Bridger dermatemyds are yet 
known which gave rise to the species living now in Central 
America ; but such probably existed ; and a member of the 
family has recently been discovered in the White River beds 
of South Dakota. Anosteira probably died out during or 
soon after the Bridger epoch. That some of the Emydidae 
of the Bridger beds were the direct ancestors of the nujner- 
ous species of Chrysemys now inhabiting North x\merica 
is very probable. Clemmys is represented in North Amer- 
ica by four species and in Europe and Asia by an equal 
number. It therefore becomes a question which continent 
"supplied the other. North America at present has the best 
claim on the genus, for the writer (Bull. Dept. Geol. Univ. 
Cal. iii, p. 237) has described one species from the Pliocene 
of Oregon and another from the Upper Miocene. 
Emys, as at present recognized, is represented by a 
single species in North America and by one quite similar in 
Europe and Asia. It is not at all improbable that the genus 
has come to us from Asia, and that from it there has been 
developed here the various species of Terrapene, or box- 
tortoises. 
The genus Hadrianus is known in North America 
from the Wasatch into the Uinta. As remarked by Lydek- 
ker, some of the early European species referred to Testudo 
may belong to Hadrianus. There seems to be no reason 
why the genus should not be regarded as having furnished 
the ancestors of the various species of Testudo which 
spread themselves over the world during Tertiary times. 
In North America genuine species of Testudo appeared in 
the lowest White River beds and continued on into the 
Pleistocene. On the other hand, it mav be doubted whether 
