= al Sil 
‘ 
P. N. Bose—History of the Extinct Carnivora. 205 
was struck by their departure from the typical Carnivora and their 
approximation to the Insectivora. ‘It is indeed questionable,” he 
says, ‘whether some of the genera here included as Carnivora are 
not gigantic Insectivora.” 
At a meeting of the Philadelphia Academy of Natural Sciences in 
1875, Prof. Cope read a highly interesting paper on the classification 
of the Eocene Carnivora. In that paper he established a suborder 
of the Insectivora under the title of the Creodonta, for the reception 
of the Wahsatch genera, Ambloctonus, Oxyena,. Stypolophus, and 
Didymictis.' In the following year he changed the name of the 
order from Insectivora to Bunotheria. Full descriptions of the 
genera just mentioned have been recently published in a beautifully 
illustrated volume *—one of the most valuable contributions to our 
knowledge of the Eocene Mammals.* 
Almost simultaneously with Prof. Cope, Prof. Huxley was struck 
with the Insectivorous affinities of the Eocene Carnivora found on 
this side of the Atlantic. In his highly suggestive and most com- 
prehensive Lectures on Biology, delivered at the Royal School of 
Mines, he noticed the remarkable fact that the flesh-eaters of the 
Hocene period, so far as they depart from the typical Carnivora, 
approach the Placental Insectivora. Instead of having recourse to a 
hypothetical Bunotherium (as Prof. Cope does), Prof. Huxley pointed 
out how, by starting with the Gymnura as the central form in the 
group of the Insectivora, we could arrive at the dentition of the other 
orders of the Mammalia. 
We propose first to consider the chief features in the dental con- 
formation of the genera mentioned above; we shall then consider 
their osteology and the structure of their brain; and finally, in the 
last section, we shall discuss their affinities and their relations 
amongst themselves as well as to the other Carnivora. 
The following table gives the stratigraphical distribution of the 
Hocene Carnivora. With regard to the Eocene of America, I have 
followed the correlation proposed by Prof. Cope, who regards 
the Wahsatch formation as Lower Hocene, and the Bridger as 
Middle Eocene.‘ I have incorporated the Stypolophus (Cope = Pro- 
totomus, Cope) with the Proviverra of Rtitimeyer, for reasons which 
will be explained in the following sections. The genus Didymictis 
too should probably be affiliated with the Palgonictis of De Blain- 
ville. 
1 Proc. Philad. Ac. of Nat. Sc. for 1875, p. 444. 
2 Report of the U. 8. Geographical Surveys, West of the 100th Meridian, part ii. 
vol. iv. Washington, 1877. 
3 Prof. Marsh described some very interesting remains of Carnivora from the 
' Wyoming Tertiary in the American Journal of Science and Arts (3rd series, vol. iv. 
pp- 126, 202), under the names Limnocyon, Viverravus, Limnofelis, Thinocyon, 
Lhinolestes, and Telmalestes. But the descriptions are very brief, and are unaccom- 
panied by figures. I am not, therefore, in a position to notice them in the present 
paper. ‘The remarkable group of the Zid/adontia established by Prof. Marsh, which 
combines the characters of the Ungulates, Rodents, and Carnivores, will be noticed 
in the last section. 
4 Proc. Ac. Nat. Sc. Philad. 1876, p. 63. 
