NATURAL SCIENCES OF PHILADELPHIA. 
21 
lection contains those of two species of Hipparion, and several peculiar genera 
of the equine family. There are also remains of several species of canine and 
feline animals, of a small species of Beaver, and of a species of Porcupine 
more nearly allied to that of the old world than to our own recent one. The col- 
lection further contains remains of a Rhinoceros, resembling that of India, 
those of a new species of Mastodon, and those of a large Elephant. 
One of the most remarkable circumstances, in relation with this extinct 
fauna, is that it is more nearly allied to the present recent one of the old world 
than to that of our own continent. From a comparison of our recent fauna 
and flora with that of the eastern continent, the deduction has been made, that 
the western continent is the older of the two, geologically speaking, whereas, 
the Niobrara fauna would indicate just the reverse relationship of age. A num- 
ber of similar instances show that totally different faunae and florae may be 
cotemporaneous, and do not necessarily indicate different periods of existence. 
CARNIVORA. 
Canis saevus, Leidy. 
Several much mutilated fragments of two lower jaws indicate a species of 
Wolf, about the size of the Canis occidentalis. 
Height of fragments of lower jaws below the 
sectorial tooth, 14 lines and 15^ lines. 
Antero-posterior diameter of the lower secto- 
rial tooth, 13 lines and 13^ lines. 
The present extinct species is not so large as the one whose remains have 
been discovered in association with those of the Megalonyx, Tapirus, Equus, 
&c., on the banks of the Ohio River, Indiana, to which the name of Canis pri- 
mcevus was inadvertently applied (Proc. Acad. Nat. Sci. vii. 200 ; Journal A. 
N. S. iii. 167),' and which may now be distinguished by that of Canis dirus. 
Canis temerarius, Leidy. 
A second species of Wolf is inferred to have existed, from two small frag- 
ments of an upper and a lower jaw, containing the sectorial teeth, and the first 
upper tubercular tooth, about the size of the corresponding parts of the Red 
Fox, Canis fulvus. 
Height of fragment of lower jaw below the sectorial tooth, 8 lines. 
Antero-posterior diameter of lower sectorial tooth, 7|- ' ' 
Antero-posterior diameter of upper sectorial tooth 7 ' ' 
Transverse diameter of first upper tubercular tooth, 6|- 
Canis vafer, Leidy. 
A third species of Canis, of small size, is indicated by the greater portions of 
both sides of a lower jaw, containing nearly all the teeth, which do not«difi"er 
in form from those of the Red Fox. 
Depth of lower jaw at the sectorial tooth, 6 lines. 
Length of entire molar series, ' 21^ " 
Antero-posterior diameter of sectorial tooth, " 
Length of crown of canine tooth, 5|- * ' 
Canis (Epicyon) Haydeni, Leidy. 
Since the preceding descriptions of wolves were written. Dr. Hayden has 
sent to me for examination a specimen belonging to the Niobrara collection, 
consisting of a much mutilated fragment of a lower jaw of a huge wolf. 
The fragment contains the sectorial molar, the two preceding premolars, and 
the sockets for the tubercular molars. The teeth preserved in the specimen 
are much worn, indicating an old individual, but they have the form of the 
corresponding teeth in the recent Wolf. The tubercular molars have occupied 
more than an inch of space, though more crowded in position than in recent 
wolves. The last, as well as the first, was inserted by widely separated fangs 
1858.] 
