2o8 The American Naturalist. [April, 
with curved rami, and short symphysis. So far as the denti- 
tion goes, I have specimens of this type from Colorado and 
from Oregon. The Oregon specimen presents the same type 
of lower jaw as does one from Texas, in my possession. Spe- 
cimens from the valley of Mexico are abundant in the muse- 
ums of the City of Mexico, and their characters do not differ 
from those from Texas. I have in my museum an entire skull, 
lacking the lower jaw. (Plate XIV.), from the" orange sand " of 
the city of Dallas, in Northeastern Texas, which only differs in 
form from that of the E. primigenius, as figured by Blumen- 
bach and Cuvier, in the shorter and wider premaxillary region. 
This is one-half wider than long (from the molar alveolus) 
