1918] Merriam: Position of Wolves of the Canus dims Group 533 



feature in the distribution of these wolves is found in their absence 

 from the Pleistocene of Fossil Lake, Oregon. The Fossil Lake deposits 

 contain a large vertebrate fauna representing a wide variety of forms 

 and ranging from the largest to the smallest mammals and birds, and 

 including representation of some of the most delicate osseous struc- 

 tures. Wolf remains are well known in this fauna, including bones 

 of both timber wolves and coyotes, but as yet no representation of 

 Aenocyon has been recognized in the collections from this locality. 

 Had Aenocyon dims or any other member of the group been present 

 in this region in numbers comparable to those known elsewhere in the 

 Pleistocene it would presumably have left at least some trace of its 

 presence. Its absence may be due to limited northern range, or to depo- 

 sition of the Fossil Lake beds at a period earlier, or perhaps later, than 

 that of Rancho La Brea and of other deposits in which specimens repre- 

 sentative of Aenocyon have been found. 



The recognized species of Aenocyon are A. dims, A. milleri, and 

 A. ayersi. 



Aenocyon dims* (Leidy) is represented in the Rancho La Brea 

 fauna by a wide variety of forms, but always characterized by large 

 size, massiveness of dentition, relatively great width of palate, and of 

 facial region. 



Aenocyon ayersi" (Sellards) is characterized by large size, rela- 

 tively narrowness of facial region compared with A. dims, massiveness 

 of dentition, and relatively wide spacing of the premolars. 



Aenocyon milleri''' (Merriam) is distinguished in comparison with 

 A. dims and A. ayersi by smaller size, relatively low sagittal crest, 

 and less prominent inion. The dentition is massive as in the other two 

 forms and the premolars are closely set, as is rather common in 

 A. dims. 



* See Merriam, J. C, The Fauna of Rancho La Brea. Part II, Canidae, Mem. 

 Univ. Calif., vol. 1, no. 2, pp. 218-246, 1912. 

 s See Sellards, E. H., op. cit. 

 8 See Merriam, J. C, op. cit. 



