8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 134 
Osborn’s (1900, fig. 8) illustration of the jaw shows the interval for 
missing M, smaller than would seem possible for this tooth in 
Ambloctonus. Moreover, Ambloctonus is not otherwise known from 
beds as late as Huerfano B or lower Bridger. 
PATRIOFELIS COMPRESSA Denison, 1938 
Type.—Left ramus of mandible with C-M, (A.M. No. 17017). 
Discussion.—Slightly larger, though close to ?P. coloradensis in 
size, this form is apparently distinguished by relatively slender pre- 
molars. No information is available on the extent to which this char- 
acter is variable in Patriofelis. It comes, moreover, from the same 
beds as ?P. coloradensis. 
KEY TO SPECIES OF PATRIOFELIS 
M, with small talonid 
IMEGY MALE eee eicte cle SMa nG b wiclel s olelaoresideites P. (Protopsalis) tigrinus 
M, without talonid 
Taree PN. Gerted SEL) Se ccsles wiainn ace wees ls P. ferox 
Intermediate size (P,-M,, 75.5-76.0 mm.) * 
VGSU Tay les erie ae cite teers sie cies ones ne as ciess-<'e P. ulta 
Small 
Lower premolars robust (P,-M,, 60 mm.)*....?P. coloradensis 
Lower premolars slender (P,-M,, 65 mm.)*..... P. compressa 
* Measurements according to Denison, except second specimen of P. ulta. 
DESCRIPTION OF THE SKULL AND JAWS OF PATRIOFELIS 
ULTA 
Attention was called by Scott (1913) to the resemblance in relative 
body proportions of Patriofelis to an otter. The short, broad, and 
low snout of the skull is perhaps even more otterlike than he had 
realized. The general appearance of the skull was not hitherto known, 
as that of Patriofelis ferox which Wortman (1892) described (A.M. 
No. 1507) was considerably restored and the portions of the top of 
the skull were evidently placed too high, so that the rostrum has the 
appearance of much greater depth than in the University of Utah 
specimen. The latter shows a small amount of crushing dorsoventrally 
below the frontal region, but it is so nearly complete that the extent 
of deformation is evident and would in no way account for the depth - 
indicated in the larger animal. 
Dorsal aspect.—In dorsal view (pl. 1) the remarkable shortness 
and breadth of the rostral portion of the skull is clearly evident. The 
nasals are broad forward but taper posteriorly to near the fronto- 
maxillary sutures on either side where they abruptly widen and then 
