114 



tooth it contains is represented in Fig. 30, Plate VI, magnified eight diam- 

 eters. 



The tooth is about a line in breadth, and, together with the alveolus baek 

 of it, occupies a space of 1\ lines. The crown of the tooth is quadrate, 

 broader than wide, and is composed of four principal conical lobes, as in the 

 squirrels, and as in its associate Paramys The sculpture and connection of 

 the lobes is different, as may be conveniently observed by comparing Fig. 30 

 with Fig. 27, representing a tooth of the same side of Paramys. It is espe- 

 cially to be noticed that in the latter the back pair of lobes include, between 

 them and the anterior lobes, a broad hollow, and the former are connected 

 behind by an acute ridge, which forms the posterior border of the crown. 

 The broad hollow of the latter is closed externally by a festoon-like ridge 

 connecting the outer lobes at their base. 



In the supposed tooth of Sciuravus (Fig. 30) the broad hollow of the crown 

 so conspicuous in Paramys and Sciurus is not evident. The posterior lobes 

 are conjoined by a transverse ridge, and are bounded behind by a thick ridge 

 descending inwardly from the postero-external lobe. The transverse valley 

 of the crown is occupied by a pair of ridges diverging from the postero- 

 external lobe to those in advance. 



Order Carnivora. 



PATRIOFELIS. 



Patriofelis ulta. 



A carnivorous animal, rather larger than our common American panther, 

 and about the size of the jaguar, to which the above name has been given, is 

 indicated by remains in the Bridger Tertiary formation. The specimens 

 from which it was originally described in the Proceedings of the Academy 

 of Natural Sciences for March, 1870, were obtained near Fort Bridger, 

 Wyoming, during Professor Hayden's exploration of 1869. They consist of 

 portions of both rami of a lower jaw, unfortunately with most of the teeth 

 lost or mutilated. The right ramus is represented, one-half the natural size, 

 in Fig. 10, Plate II. 



The jaw of Patriofelis contains a series of five molar teeth immediately 

 succeeding the canine tooth without conspicuous interval, as in some of the 

 viverrine and musteline animals. The molar teeth are all inserted by a pair 

 of fangs, and none of them appear to be of the purely tubercular kind. The 



