168 M. R. Thorpe — Oregon Tertiary CanidcB 



shows an exceedingly small incipient one, while the poste- 

 rior basal tubercle is much smaller than in T. ferox, but 

 practically the same as in the type. Merriam 1906 (p. 23) 

 says that T. altigenis is characterized by the absence of a 

 posterior basal tubercle, but in the absence of other diver- 

 gent characters, I do not consider that this tubercle on 

 P 3 invalidates the identification with this species. 



Measurements. 

 (Cat. No. 10065, Y. P. M.) 



mm. 



Skull length, prosthion to occip. condyles, inc 205* 



Diameter of brain-case 62 



Diameter of postorbital constriction 32.3 



Bizygomatic diameter 120 



Length of molar series 20 



Length of P^ 19 



Transverse diameter across deuterocone of P 1 14.5 



* Approximate. 



Mesocyon coryphceus (Cope). 



This species was very abundant in the John Day Basin 

 and is represented in the Marsh Collection by some excel- 

 lently preserved skulls with jaws. Cat. No. 12702, Y. P. M., 

 collected at Turtle Cove, differs in some respects from the 

 type as described and figured by Cope. It is about 10 mm. 

 shorter than the type, but the postorbital constriction is 

 one-third greater than that of Cope's specimen, while the 

 latter shows a little greater bizygomatic diameter. The 

 muzzle is 24.5 mm. in minimum transverse diameter ; in 

 the type it is 30.2 mm. The superior canine of the Yale 

 specimen is much more slender and recurved. The supe- 

 rior tooth measurements correspond more closely to those 

 of No. 1383, Univ. Calif. Coll. Vert. Pal. (Merriam 1906, 

 p. 19) than to the type. The junction of the temporal 

 ridges lies 16 mm. posterior to the postorbital constric- 

 tion and in the type it is nearly above the constriction. 



Cat. No. 12703, Y. P. M., also found at Turtle Cove, is a 

 skull and jaws, which, in the main, lack only the zygomata 

 and some of the incisors. This is a typical example of the 

 species. I > 1 is very much reduced ; the posterior tubercle 

 of P 3 is fairly prominent, but the one on P 4 is very heavy 

 and prominent; the masseteric fossa very large and 

 deep. 



