HATCHER : OLIGOCENE CANID^E 105 



Cynodictis Gregarius Cope. 



There are in our collections a number of skulls associated with more or less 



complete skeletons which I have referred to the above genus and species. With the 



exception of the os penis which has already been described, these remains throw no 



new light on the osteology of that genus of Oligocene dogs and hence require no 



further reference here. 



Conclusions. 



The principal object in the preparation of the present paper has been to give to 

 students of the Canidse, in so far as possible, an accurate description of the osteology 

 of Daphoenus felinus, supplemented by good figures based upon the skeleton of a 

 single individual. With the exception of the scapula, pelvis, and certain of the 

 vertebrae and sternals our skeleton, No. 492^ is exceptionally complete and thus 

 affords a safe and reliable guide to the osteology of at least one species of Oligo- 

 cene dogs. After a prolonged and careful comparative study of this skeleton, to- 

 gether with the associated material in our collections, the present writer was forced 

 to the conclusion that among the larger White River Canidfe there are represented 

 three distinct genera two of which had been previously unrecognized, all having 

 been heretofore referred to the single genus Daphoenus. Of these three genera two, 

 Daphoenus and Proamphicyon, include species which are larger than those of the 

 third and may be referred to collectively as dolichocephalic or long-skulled, while 

 those belonging to the third genus, Protemnocyon, are smaller and brachycephalic 

 or short-skulled. 



Briefly these three genera, which in fact represent three distinct phyla, may be 

 characterized as follows : 



1. Daphoenus. — Skull elongate, sagittal crest high, brain-case reduced, canines stout 

 and round without anterior or posterior cutting edges, preraolars strong and, save in D. 

 DODGEi, ivith M.- small and aligned with internal cones of preceding molars, position of 

 vertehrarterial canal in atlas as in the ccds. No known descendant. 



2. Proamphicyon. — Skull elongate; sagittal crest high; brain-case reduced; canines 

 long, compressed and with posterior cutting edge ; premolars much reduced in size and 

 I veil spaced; M.^ large with two roots? Ancestrcd to Amphicyon of the Loup Fork. 



3. Protemnocyon. — Skull short; sagittal crest low ; brain-case large; canines com- 

 pressed but without cutting edges; premolars strong and rather closely set; M.^ very small 

 or absent; position of vertebrarterial caned of atlas intermediate between dogs and cats ; 

 ancestral to Temnocyon of the John Day. 



Concerning the very difficult subject of the relations of the Oligocene canidse to 

 recent forms, the present writer does not feel competent to enter into a discussion. 



