Vol. 5] 



Mcrriam 



. — John Day Garnivora. 



17 



A well-preserved mandible (No. 1307) shows the type of den- 

 tition in M. coryphaeus. The sectorials are somewhat worn, so 

 that no internal tubercle is shown. The tnbercnlars are very im- 

 perfectly preserved. On another specimen (No. 10366) the last 

 two premolars, the sectorial, and the first tubercular are perfectly 

 preserved. The measurements of these jaws, as also of several 

 detached teeth, are considerably less than those of the type of 

 M. coryphaeus, as is indicated in the measurements below. Al- 

 though Cope states that the mandible described by him was asso- 

 ciated with the smallest of the several skulls available, I find that 

 the dentition of mandible No. 1307 in our collection fits the denti- 

 tion of the skulls of coryphaeus, particularly that of No. 1165, 

 very closely, and seems also to have the dimensions required for 

 the mandible of the type cranium. The measurements available 

 seem to indicate considerable variation in size among the forms 

 of this group. 



MEASUREMENTS. 10 



Mi, antero-posterior diameter 



Type 

 18 



No. 

 13 7 



16.5 



No. 



5 9 9 



15 



No. 

 1 3 6 fi 

 14.5 



M,, antero-posterior diameter 









7.3 



P 4 , antero-posterior diameter 



11 



10 





10.5 



P„ antero-posterior diameter 





9.4 





8.7 



Height of jaw below protoconid of Mj 



19.3 



17 





18 



Height of jaw below protoconid of P 2 





15 







MESOCYON BRACHYOPS, n. Sp. 

 Text-figure 2. 



Type specimen No. 1692, Univ. Cal. Col. Vert. Pal. From the upper por- 

 tion of the John Day series at Logan Butte, Crook County, Oregon. 



Facial region and palate relatively shorter than in either 

 M. coryphaeus or M. josephi. Superior dental series somewhat 

 crowded anteriorly, so that P 1 is very close to the canine. Supe- 

 rior sectorial and first tubercular with dimensions near those of 

 coryphaeus, and absolutely larger than in josephi. The brain 

 case is relatively larger than in coryphaeus. 



10 See also measurements of superior dental series of coryphaeus below, 

 p. 19. 



