ON SOME NEW AND LITTLE KNOWN CEEODONTS. 
183 
shows beneath it a tubercle for the attachment of the tendon, -which, however, forms 
no such process as in the cats. At its free end the phalanx is deeply cleft for nearly 
half its length. This claw tends to confirm the inference drawn by Gervais and 
others, from the structure of the palate, as to the aquatic habits of the genus, and it 
proves conclusively that the hind leg and foot which I formerly referred to Hycenodon, 
belongs to some very different form. 
There is still much doubt as to the structure of the carpus in the European 
species Hycenodon, Professor Cope states’ that in a specimen of H. requieni, from 
Desbrusges, in the Jardin des Plantes, the scaphoid and lunar are coossified. On the 
other hand De Plain ville’s figure of H. parisiensis agrees very well with the speci- 
men just described, and seems to show the impression of a separate lunar. 
The only part of the hind-limb preserved is the ilium; this is rather feline in 
character, being but slightly expanded and showing a deep gluteal surface. 
This survey of the osteology of Hycenodon brings out some important and, appar- 
ently, constant differences between the American and European species of the genus. 
More perfect knowdedge of the French species will not improbably necessitate the di- 
vision of the genus Hycenodon as now understood, and the revival of De Blainville’s 
name Taxothermm ; his figure of T. parisiensis shows no alisphenoid canal, agreeing 
with the American species; though this may, of course, be an oversight. The name 
Taxotherium would, in this case, include those species which have separate scaphoid, 
lunar and central bones in the cai-pus, no alisphenoid canal, cerebral hemispheres not 
broader than the cerebellum, and with straight convolutions. The name Hycenodon 
would then be limited to the species with coossified scaphoid and lunar, an alisphe- 
noid canal, hemispheres with winding convolutions and broader than the cerebellum. 
It would be premature to make this division until the reference of the French speci- 
mens of carpus and brain can be cleared up. 
As far as the American species are concerned, their systematic position can now 
hardly be a matter of doubt. M. Gaudrey’s view as to the marsupial character of the 
genus is definitely disproved by the abundant material now at command. Some resem- 
blances to Thylacynus, it is true, are apparent: but these features are also common to the 
Insectivora, and only the dentition can be supposed to indicate remote marsupial affini- 
ties. M. Filhol,^ on the other hand, contends that Hycenodon is a true carnivore, but 
the teeth, the carpus and the vertebrae forbid any such reference of the American 
species, and even if furthur investigation should show that most of the French species 
have the scaphoid and lunar cobssified and thus necessitate the revival of Taxotherium, 
it would be a very unnatural and arbitrary mode of classification to place two such 
closely allied genera in different orders. The character of the dentition is alone suffi- 
cient, it seems to me, to forbid the reference of Hycenodon to the Carnivora. 
1 Tert. Vert., p. 256. 
Loc. (it. 
