Art. XTI.— On the Caiiidse of the liOiip Fork Epoch. 



By E. D. Cope. 



In the sixth volume of the Bulletin of the Survey, commencing at page 

 177, I gave an account of the Canidce of the White River period, in its 

 two subdivisions, the White Eiver and Truckee epochs. Fourteen 

 species were enumerated. At present I give a brief review of some of 

 the species of the succeeding or Loup Fork formation, whose age I have 

 placed as the highest Miocene. The number of species is not so large 

 as that found in the preceding period, and those that are known ap- 

 proach more nearly in character the existing dogs. Some of them ex- 

 ceed in size any of those of the other period, and none are so small as 

 the least of the White Eiver forms. 



Dr. Leidy has described the Canes haydeni, saevus, temerarius and 

 vafer, and I have added Canes ursinus and wJieelerianus^ and Tomarctus 

 hrevirostris. 



Dr. Leidy also described an ^lurodon ferox, whose affinities he did 

 not decide, but which he thought to combine characters of dogs and 

 cats. I am able to prove by material now in my possession, that the 

 ^lurodon ferox and the Cams swvus are the same species. The genus 

 JEhirodon must be added to the Canidw, and distinguished from Canis 

 proper only by the presence of an anterior cutting lobe of the superior 

 sectorial tooth, the character on which Dr. Leidy originally proposed it. 

 There are three species of the genus known to me, the ^. saevus, JE. 

 wheeleriamis {Canis Cope), and a new one which I propose shall be called 

 JE. liymioides. The character of the superior sectorial tooth above 

 mentioned is as much like that of Hyaena as Felis, and the entire tooth 

 in the ^. hyoinoides is much like that of the former genus. In all three 

 species the premolars are very robust, as though to aid the sectorials in 

 crushing bones, as they do in the hyajnas. The second metacarpal 

 bone has on its inner surface a rough area of insertion, such as is pres- 

 ent in the dogs and absent in the hyaenas, and which may indicate five 

 digits in the anterior foot, the general character of the Canidw. 



^LURODON SAEVUS Leidy. 



Canis saevus Leidy, Proceed. Acad. Pbila.. 1858, p. 21.— JEIurodon ferox Leidj, 

 1. c, 1858, p. 22 ; Extinct Mammalia Dakota and Nebraska, Plate I, Figs. 9 

 and 13, 14. 



I have a large part of the skeleton, with entire skull, of an individual 



387 



