456 HVAENODON AND PATRIOFELIS CHAP. 
long, and the top has a great sagittal crest. The paroccipital 
processes are short and are closely applied to the mastoid processes. 
The mesethmoid is larger than in the carnivorous Marsupials, and 
the frontals are very large. The palate has a peculiar structure ; 
in most species the hinder ends of the palatines are separated 
by a narrow fissure which broadens gradually, thus forming the 
posterior nares. In HH. leptocephalus the posterior nares are brought 
very far back by the meeting of the alisphenoids. The pre- 
sphenoid, contrary to what we find in the Dog, for example, is 
chiefly concealed by the vomer, which covers it. The mandible 
has a long and strong symphysis, and its angle is not inflected. 
The fore-limb is described as being “ weak when compared with the 
modern Carnivora.” The scaphoid and lunar are separate, and 
there is a centrale. The teeth present us with nearly the typical 
formula. There is only one molar missing in the upper jaw. The 
canines are enlarged. It has been suggested from a consideration 
of its palate that Hyaenodon was a semiaquatic animal; the 
deep cleaving at the extremities of the phalanges seems to point 
in the same direction, since they resemble in this the genus 
Patriofelis, which there are other reasons to regard as aquatic. 
This latter genus has a fore-limb which is very like that of the 
Pinnipedia, the digits are much spread out, and would seem 
to have supported a kind of paddle. In any ease it certainly 
fed upon aquatic tortoises, for their remains have been found in 
its coprolites. The name Limnofelis, also apphed to what appear 
to have been members of this genus, is suggestive of their habits. 
Patriofelis, at least one species, seems to have been of about the 
size of a Lion. 
Mesonyx has a brain case which is actually smaller than that 
of the Marsupial Zhylacinus. The lachrymal bone is very large, 
and extends a little way over the face, as is also the case with 
Hyaenodon ; this condition is also found in Insectivora and in 
Thylacinus. The axis vertebra has a curiously-shaped spine, 
which is very different from the hatchet-shaped process of that 
vertebra usual in the Carnivora, but is not unlike what exists 
in the Arctoid genera Meles and Mydaus. The limbs show 
much disparity in length, and seem to argue a much-arched 
back when the creature progressed. The carpus is stated to 
be strikingly like that of the Insectivora. There is as in 
other Creodonts a separation between the scaphoid and lunar; 
