XIV ANCIENT CARNIVORES—CREODONTA 455 
incommoded by the direct rays of the sun, to the effects of 
which they are very susceptible. The Elephant Seal is mild 
and inoffensive, unless enraged, and, of course, during the 
breeding season. 
Order VIII. CREODONTA. 
This entirely extinct group of Mammalia may be thus character- 
ised :—Small to large carnivorous mammals, with skull on the 
whole like that of the Carnivora and with trenchant teeth ; digits 
with unguiculate phalanges; tail long; extremities usually with 
five, sometimes with four digits. In the carpus a centrale is 
present, and the scaphoid and lunar are separate. Interlocking 
of posterior dorsal and lumbar zygapophyses very perfect. Brain 
small but convoluted. 
This group, which corresponds with the CARNIVORA PRIMI- 
GENIA of Mr. Lydekker, is not easy to separate absolutely from the 
existing and more especially from some of the extinct members 
of the CARNIVORA VERA. They also come exceedingly near the 
Condylarthra, the presumed ancestors of the Ungulata, and like 
them begin in the earliest Tertiary deposits. Their likeness to 
the carnivorous Marsupials has also been insisted upon; but it 
would seem that the succession of teeth in the Creodonta is 
typically Eutherian. 
The characteristics of the group may be exemplified by an 
account of the genus Hyaenodon, after which some of the more 
important deviations in structure shown by other genera will be 
referred to. 
Hyaenodon is both American and European, and ranges 
through the Eocene and the Upper Miocene. It is a much- 
specialised Creodont, and therefore exhibits well the distinctive 
characters of the group. About a dozen species have been 
deseribed. One of the best-known is the American //. erventus, 
and the following description refers to it. The back part 
of the skull is low and broad, and is compared by Professor 
Scott (who has described this and other species) as being 
“somewhat like that of an opossum.”' The whole skull is 
1 Journ. Ac. Sci. Philadelphia, ix. 1886, p. 175. 
