1919] Merriam: Tertiary Mammalian Faunas of Mohave Desert 519 



the skull the portion of a horn attached shows the burr about one-half 

 an inch above the orbit. 



In skull specimen no. 21551 (figs. 125a, 125/;) the characters are 

 near those of the fine specimen of Merycodus osborni, figured and 

 described by Matthew. 33 



In the Barstow species the brain case seems narrower, the orbits 

 a little less prominent, and the antlers are situated a little farther 

 forward on the orbit than in M . osborni. 



The frontoparietal suture in M. osborni is almost identical in 

 position with a line connecting the posterior sides of the antler bases. 

 In the Barstow species the suture bows far back of the antler bases. 



Figs. 125a and 1256. Merycodus, sp. Skull, no. 21551, X %. Fig. 125a, 

 lateral view; fig. 125b, dorsal view. Barstow Miocene, Mohave Desert, California. 



The mandible of the Barstow form has approximately the dimen- 

 sions of the forms figured by Cope 34 and referred to M. necatus, and 

 the dimensions of the inferior cheek-tooth series are also similar. The 

 maxillary is known only by small fragments. 



The degree of hypsodonty of the molars is greater than in the 

 Virgin Valley forms, so far as known, and much less than in the 

 Pleistocene Capromeryx. M 3 has a strong hypoconulid lobe, which 

 in some cases (no. 21490, fig. 130) approaches the size of the second 

 or hypoconid-entoconid segment of the tooth. No suggestion of divi- 

 sion of the posterior lobe of M 3 has been noted more than the presence 

 of a faint concavity on the posteroexternal side of the third lobe 

 (figs. 129, 130). The inferior premolars (figs. 128 and 131a) are 

 moderately hypsodont. The postero-external fold is generally strongly 

 marked almost to the base of the tooth. 



33 Matthew, W. D.. Bull. Am. Mus. Nat. Hist., vol. 20, p. 106, 1904. 



34 Cope, E. D., U. S. Geog. Surv. West of 100th Meridian, vol. 4, p. 82, 1877. 



