DAKOTA AND NEBRASKA. 69 



sands of tlie Niobrara River, in association with those of the wolves described m the 

 preceding pages. It is perfect, unworn, and is represented in figures 1-3, 14, plate I. 



The tooth belonged to an animal equal in size, if not somewhat larger than the 

 largest variety of the existing American "Wolf, Canis occidentalis, or its European 

 representative, the Ganis lupus. It perhaps may have appertained to the same 

 animal as the jaw fragment referred to Canis Haydeni, though its size appears too 

 small in relation with the sectorial molar of the latter, in comparison with the 

 corresponding teeth of the recent Wolf K subsequent discoveries should determine 

 the two fossils to belong to the same animal, their distinctive characters together are 

 amply sufficient to refer them to a distinct genus, for which the name of Epicyon, 

 originally applied to Canis Haydeni, would be appropriate. 



The tooth is intermediate in character to that of the wolves and cats. Larger 

 than in the largest variety of the recent Wolf of America or Eurojae, it approaches in 

 size to that of smaller individuals of the Bengal Tiger, Fells tigris. 



The crown is longer, but not so broad as in the latter animal, the two measure- 

 ments holding moi'e the proportion to each other as in the wolves. It differs 

 strikingly from that of the latter, as in the cats, in the possession of an accessory 

 lobe in advance of the principal cusp, but pi'oportionately less well-developed than in 

 the Tiger. The principal cusp is better developed than in the latter animal, being 

 both longer and broader. The posterior trenchant lobe is longer, but not so broad as 

 in the Tiger. A tubercle at the antero-internal part of the crown, supported on the 

 abutment-like projection of the base of the principal cusp, and sustained on the 

 advanced antero-internal fang of the tooth, is not so well-developed as in the cats, 

 but is about equal to that of the wolves. 



In fewer words, the tooth has the proportions of that of the wolves, but has added 

 to it the anterior accessory lobe of that of the cats. 



The measurements of the tooth, in comparison with that of a Bengal Tiger from 

 Hindostan and that of a Wolf from Germany, are as follows : 



Antero-posterior diameter of crown externally, 

 Antero-posterior diameter of cro'SVTi internally, 

 Length at principal cusp. 

 Length at posterior lobe, 

 Tliickness of base anteriorly, . 

 Thickness at base of principal cusp, . 



A. ferox. 



C. lupus. 



F. tigris 



Lines. 



Lines. 



Lines. 



. 13 



12h 



15 



. 14i 



12J 



14 



. 8J 



7i 



Ih 



. 7 



6 



6 



. 7J 



6 



7i 



. 5i 



5 



5 



