PALEONTOLOGY. 311 



Hay, Oliver P., U. S. National Museum, Washington, District of Columbia. 

 Associate in Paleontology. (For previous reports see Year Books Nos. 

 11-16.) 



Since the last report was rendered Dr. Hay has been working mostly 

 on the Pleistocene geology and vertebrate paleontology of the Atlantic 

 coast plain from southern Florida to Massachusetts. Some of the 

 conclusions thus far reached on Pleistocene geology and on the history 

 of its vertebrated animals he states as follows: 



1. At an early time in the Pleistocene period the vertebrate life of 

 our continent was extremely rich. That of the present time is relatively 

 greatly impoverished. 



2. It is impossible to say to what extent new species have been 

 developed since the beginning of the Pleistocene. It would be unsafe 

 to say that any particular existing species did not live during the first 

 interglacial stage. 



3. The species and genera of vertebrates suffered extinction during 

 the Pleistocene to a surprising extent. Of a list of over 600 reported 

 species, nearly 60 per cent are extinct. Among these are several 

 genera of ground-sloths, two genera of mastodons, three or four 

 species of elephants, as many of camels, two species of tapirs, many 

 species of horses, many of bisons, several species of peccaries, and 

 various tiger-like cats and saber-tooth cats, 



4. The five glacial stages and the stages of mild climate that suc- 

 ceeded each of them furnish us a means for determining, in at least a 

 general way, the times when many important species became extinct. 

 The camels, nearly aU of the species of horses, species of Hipparion, 

 Elephas imperator, the species of mastodons belonging to Gompho- 

 therium, the edentates belonging to Megatherium, Glyptodon, and 

 Nothrotherium, appear to have died out before or during the Kansan 

 glacial stage. The tapirs, the few remaining horses, the long-horned 

 bisons, the saber-tooth cats, and Mylodon probably disappeared before 

 the oncoming of the Wisconsin ice-stage. Two species of elephants, 

 the common mastodon, species of peccaries, the giant beaver, Mega- 

 lonyx, and the moose Cervalces persisted through the vicissitudes of 

 several stages and then succumbed v/hen conditions appeared to be 

 wholly favorable for their existence. 



5. The low-lying formations known as Cape May in New Jersey, 

 most, perhaps, of the Talbot of Maryland, and the Pamlico of North 

 Carolina appear to have the age of the Wisconsin. Their few known 

 vertebrate fossils favor this assignment. The older formations, known 

 in New Jersey as Bridgeton and Pensauken, in Maryland as Sunder- 

 land and Wicomico, in North Carolina as Coharie, Sunderland, Wico- 

 mico, and Chowan, appear to have approximately the age of the first 

 interglacial, the Aftonian. An Aftonian fauna is present at Vero, Flor- 

 ida, and at Charleston, South Carolina. By the presence of horses 



