ivith Descriptions of Neiv Forms. 169 



Measurements. 

 (Cat, No. 12703, Y. P. M.) 



mm. 



Length of ramus, angle to incisor border, inc 122 



Length of inferior dental series with canine 78 



Length of inferior premolar series 37 



Length of inferior molar series 27 



Depth of ramus below middle of M 1 17.5 



Specimen No. 12704, Y. P. M., from Turtle Cove, is the 

 anterior part of a skull with some teeth. It is an old indi- 

 vidual, with the teeth much worn. These teeth are more 

 robust and heavier than in the type or in the other Yale 

 specimens of this genus. M 2 is nearly a third wider 

 antero-posteriorly and 1 mm. greater in transverse diam- 

 eter than the type M 2 . The individual tooth measure- 

 ments are close to those of M. br achy ops Merriam, but 

 the total length from the posterior edge of M 2 to the poste- 

 rior edge of the canine is 2 mm. greater than in the type of 

 M. coryphceus. Merriam (1906, p. 17) found a consider- 

 able variation in size within this species and the Yale 

 specimens apparently confirm this opinion. I suspect 

 that this latter specimen, Cat. No. 12704, represents a 

 male. 



Mesocyon brachyops Merriam. 



Cat. Nos. 12710 and 12719 of the Marsh Collection, from 

 Bridge Creek and Turtle Cove, respectively, consist of 

 maxillae with parts of premolar and molar series. They 

 are from upper John Day strata. 



Mesocyon josephi josephi (Cope). 



A nearly complete skull with mandibles attached, Cat. 

 No. 12705, Y. P. M., is very close to the type. It was col- 

 lected in middle John Day strata in the Fossil Horse beds 

 on Cottonwood Creek. This species has been known here- 

 tofore only from an anterior part of a skull with teeth. 

 The description may be amplified as follows : 



Specific characters. — About 12 per cent shorter in total 

 length than 21. coryphaeus; muzzle short; infra-orbital 

 foramen above the interval between P 3 and P 4 ; postor- 



