O. C. Marsh— Vertebrate Life in America. 343 
in the Triassic, a few oheractenietows pemaine have. been found. 
ctory, an 
this class can be based upon them. rom the Jurassic and 
Cretaceous beds of this Continent, no remains of Amphibians 
are known. A few only have been found ‘in the ertiary, 
and sees are all of modern t, 
berry, Leidy Cope, Dawson, Agassiz, St. John Gib es, , Wy- 
man, Redfield, and Emmons, and the pionpe literature of the 
subject will be tonans in their publication 
Reptiles and Birds form the next om eat division of ver- 
tebrates, the Sauropsida, and of these the Reptiles are the older 
type, and may be first considered. While it may be stated 
with certainty that there is at present no evidence of the exist- 
ence of this group in American rocks older ve the Car- 
boniferous, there is some doubt in regard to their appearance 
even in this period. Various foot- prints which eee resem- 
ble those rl by Lizards; a few well preserved remains similar 
In the Permian rocks of tonne Reptiles have been 
found. 
odon, Ww Ss WwW iso | 
Roan It belongs to the Thecodont division of Reptiles, 
which have teeth in distinct sockets, and its nearest affinities 
