1880. | On the Extinct Cats of America. 857 
the name of Trucifelis fatalis. As it possesses a second anterior 
basal lobe of the superior sectorial, it is doubtless a Smzlodow. I 
am confirmed in this opinion by the characters presented by an 
important specimen sent me by G. W: Marnock, who obtained it 
in Southwestern Texas. It consists of 
that portion of a cranium, which is 
posterior to the orbits, and represents 
an animal of the size of the S. neca- 
tor, or of a large tiger. The positions 
of the foramina and the conjunction of 
the posttympanic and postglenoid pro- 
cesses are as in the S. necator. When 
more of this species is known, it will 
doubtless be found to be our largest 
sabre-tooth. 
Among the remains obtained by - 
Charles M. Wheatley from a cave on 
the Schuylkill river, in Pennsylvania, 
which I described in 1871, there oc- 
curred a part of the canine of a sabre- 
tooth. Hoping to obtain better speci- 
mens, I did not include it in the pub- 
lished lists. Having established the 
existence of the genus*Swilodon as a 
contemporary of the sloths during the 
Pliocene period in North America, it 
becomes probable that the species of 
the caves is also to be referred to it. 
The canine in question has lost most 
of its crown. It is of smaller size than 
that of either of the three species pre- 
viously mentioned, and its basal por- 
tion is more compressed. This com- 
pression is a marked character, and I 
refer to it the name Smilodon gracilis, 
by which the species may be known. 
Uncia Gray (Cope emend.). 
Extinct species of this genus have 
been found in the late Miocene and subsequent deposits in 
India, Europe and North America. It is distinguished from the 
Fic. 15. — Dan necator; 
humerus of s en Figs. 12, 
13, from front, one- e-third natural 
size. Mus. Co} 
