32 



University of California Publications. 



[Geology 



incisor evidently representing' I, or I 1 was found loose in the 

 matrix with the mandible. It would occupy only about half of 

 the empty alveolus, but if the other incisor was present, one of 

 them must have been crowded far back. 



The canine is large and is somewhat heavier than in most of 

 the associated canid forms. 



Of P t there is no trace, though the alveolar border is per- 

 fectly preserved, and as P 2 is large and very near the canine, its 

 absence is evidently normal. All three of the premolars are 

 rather heavy. The first two are set somewhat obliquely in the 

 jaw. All three are two-rooted. P. has no distinct anterior or 

 posterior tubercles, though the cingulum is slightly swollen ante- 

 riorly and posteriorly. P.. has a minute anterior basal tubercle, 

 a posterior cusp, and an incipient posterior basal tubercle. The 

 general structure of P 4 is similar to that of P.., but the basal 

 tubercles and posterior cusp are better developed. 



The shear of the trigonid on M x is thick at the base and the 

 blades are relatively higher than in Canis. The metaeonid is 

 about as large as in Canis. On the talonid, the base of the hypo- 

 conid does not reach inward beyond the middle of the heel. The 

 summit of this cusp is laterally compressed, but is not as high as 

 in Temnocyon. The inner half of the talonid is slightly exca- 

 vated, and there are two small tubercles corresponding to the 

 entoconid and hypoconulid on its inner and posterior borders. 



M 2 shows a well-developed protoconid and metaeonid, the for- 

 mer being somewhat the larger. On an excavated antero-internal 

 shelf a low marginal ridge represents the paraconid. The heel is 

 slightly hollowed and the outer border is a little higher than the 

 inner. 



The structure of the small M 3 is so far as known in general 

 similar to that of M 2 , though the paraconid shelf is smaller. 



Affinities. — The type of canid described above shows consider- 

 able resemblance to the short-faced dogs which have been grouped 

 together in the sub-family Simocyoninae. Of these there are 

 known from the John Day three genera, Oligobunis, Hyaenocyon, 

 and Enhyclrocyon, no one of which corresponds closely to the 

 form under discussion. 



