THE PLEISTOCENE. 
Following the terminology of Dana, the Pleistocene of North 
America has two well limited periods, the Glacial and the Cham- 
plain, the former characterized by the prevalence of glacial condi- 
tions, the latter by fluvial, by an ameliorated climate, luxuriant 
forest growths, and more or less submergence. The third period 
of the Quaternary, the Recent, is characterized by a partial return 
to the colder climate, the elevation of the land, the development 
of the prairies, and a drier climate. It is precisely at this time, 
that of the change from the warmer and moister climate to the 
colder and drier one, that we would expect the culmination of the 
more susceptible forms of life and rapid change in the flora and 
fauna. Cope has already called attention to this change in an 
article that I will quote from further on. Every additional fact 
furnished from Kansas seems to substantiate his conclusions that 
the Megalonyx fauna of the east and the Equus fauna of the west 
were contemporaneous and that both occurred during the period of 
depression, that is during late Pleistocene time. It is strange that 
some writers should still follow Marsh in his location of the Equus 
fauna in the Pliocene. That Marsh does so is not surprising, since, as 
Hatcher has shown, he has confounded the Loup Fork and Equus 
faunas in part, and seems to be unaware of recent publications on 
the subject. 
That there was a depression in Kansas during Champlain times 
is certain. That this depression was considerable I do not believe, 
inasmuch as the river terraces in the eastern part of the state no- 
where exceed twenty feet in total height.. 
“The Equus beds are always to be distinguished by the presence 
of Elephas primigenius, when other forms less easily preserved are 
not recognized.”! This species is the most common fossil, or at 
1 Cope Vert. Pal. Lian. Estac. p. %5. 
(299) 
