228 



[f the upper sectorial molar of Felis atroz had the same proportionate size 



to the lower one as in the Bengal tiger and oilier feline animals, \\ measured 

 uearly an inch and three-fourths in breadth. That of the Loup Fork fossil 

 is a little over an inch and a quarter in breadth. From the difference in size, 

 thus indicated between the sectorial molar of the Loup Fork fossil and thai of 

 the previously described largest American cats, recent and extinct, we may 

 fairly regard the specimen as characteristic of another species, for which the 

 name heading this chapter has been proposed. 



Comparative measurements of the upper sectorial molar are as follows — 

 those from Felis atrox being estimated, and that from the jaguar being taken 

 from Plate XIV of De Blainville's Osteographie: 



Upper sectorial molar. 



F. coucolor. 



F. ouca. 



F. augustus. 



F. tigris. 



F. atrox. 



Breadth of crown 



Thickness in front 



Lines. 

 11 



Lines. 

 12 



Lines. 



15J 



8 



Lines. 



10 



Lines. 



20 

 10 







Another specimen, represented in Fig. 18, Plate VII, consisting of a frag- 

 ment of a premaxillary retaining the second incisor, the first alveolus, and part 

 of the last one, agrees in size and other characters with the corresponding 

 part in the Bengal tiger. 



The remaining specimens are fragments of au upper last premolar and of a 

 canine from the same individual. 



A specimen, represented in Fig. 24, Plate XX, found by Professor Hayden 

 on the Niobrara River, but not in proximity with the preceding, consists of 

 the distal extremity of a humerus, probably of the same animal. It has 

 about the same size, proportions, and form as in the corresponding part of 

 the arm-bone of the Bengal tiger. Its diameter at the supracondyles is 3f 

 inches ; the breadth of the articular surface in front is 2f inches. The hole 

 for t,he brachial blood-vessels and accompanying nerve is quite evident, though 

 the bony bridge defining it is broken. 



Felis imperialis. 



Among a collection of fossils belonging to the cabinet of Wabash College, 

 Crawfordsville, Indiana, purchased from Dr. Lorenzo Y. Yates, of Centreville, 

 Alameda County, California, there are several which were kindly loaned to 



