Report of the Sub-Committee on the Ceno- 
zoic (Interior). 
E. D. COPE, 
REPORTER. 
CENOZOIC REALM.* 
This Realm is distinguished from the Cretacic, as well as from 
the Mesozoic formations as a whole, in North America by the 
following peculiarities. In Vertebrata : 
By the presence of Dip] arthrous Mammalia. 
« " of Rodent " 
" " of Nematognath Fishes. 
" " of Plectospondylous Fishes. 
" " of Osteoglossid " 
" " of Pharyngognath " 
" absence of Multituberculate Marsupial Mammalia. 
" " of Orthopod and Goniopod Dinosauria. 
" " of Plesiosaur Eeptilia. 
" " of Pterosaur Eeptilia. 
" " of Choristodere Rhynchocephalia. 
The primary systems of the Cenozoic Realm are 
Plistocene, 
Pliocene, 
Miocene, 
Eocene. 
Although open to conviction, I have not perceived the neces- 
sity for the term Oligocene for a supposed system between the 
Eocene and Miocene. In America the faunal distinction between 
the latter is so obliterated as to render a third name, for the present 
at least, unnecessary. I have also not adopted the term Quater- 
* Prof. Cope objects to the word " Group " for the division of geological for- 
mations of the first rank and proposes to substitute the word " realm " therefor. 
