VERTEBRATES FROM MIOCENE, PLIOCENE AND PLEISTOCENE. 99 
fully known the American species may be found to be generically 
distinct from the European species. 
The jaw which serves as the type specimen of the species is 
from an old individual and the teeth are well worn. At the front 
of the jaw may be seen sockets for the three incisors which were 
small and crowded in the jaw. , The very large canine is present 
although much worn. Of the premolars there is preserved Pm 4 
and an alveolus for an additional tooth close to the canine. 
Whether or not the other two premolars were present cannot be 
determined. The jaw is well preserved and there is no indication 
of alveoli for the missing premolars. If these teeth were present 
they must have dropped out early from this jaw, the alveoli hav¬ 
ing subsequently disappeared. Of the molar series there is pre¬ 
served, M x and M 2 , and the alveoli for M 3 . 
The striking features of the jaw are the very large molars and 
canines and the proportionate reduction of the premolars and inci¬ 
sors. Of the mo'lar-premolar series the molars occupy about two- 
thirds, and of the entire dental series about one-half. The jaw 
as a whole is short, strong and its inferior margin convex. 
MEASUREMENTS. 
Length of the jaw front to angle, about-260 mm. 
Height of jaw at Mi- 73 
Width of jaw between the incisors- 40 
Length of molar-premolar series- 145 
Length of molar series from posterior margin of alveolus for Ms to the 
anterior margin of Mi- ; - 90 
Mi anteroposterior _ 40 
Mi greatest transverse width of heel- 23 
M 2 anteroposterior _ 26 
M 2 greatest transverse width_!- 20 
Ms anteroposterior measurement of alveolus- 20 
Ms transverse measurement of alveolus_ 12 
Pm, anteroposterior_ 22 
Pm, greatest transverse width_ 14 
Canine, anteroposterior_ 36 
The known old-world species of this genus have three premo¬ 
lars, interpreted as Pm 2 , Pm 3 , and Pm 4 , thus differing from the 
Florida fossil in which there are but two premolars, probably Pm 2 
and Pm 4 .. As compared to Agriothcriiim ( Hyacnarctos ) punjab- 
iensis, which is of approximately the same size, the canine teeth 
