EXTINCT MAMMALIA OF NORTH AMERICA. 373 



Recently a fine specimen, consisting of the cranial portion of a skull, together with 

 both horn cores, of a large extinct Ox, has been presented to the Academy by Wal- 

 ter Brown, of San Francisco, California, through William M. Gabb, of the California 

 Geological Survey, The fossil was obtained from Santa Clara County, California. 



In size and proportions it is nearly related with the specimen originally referred to 

 Bison antiquus. It also sufficiently resembles the fossil from Eschscholtz Bay, 

 described by Buckland and Richardson, and referred by the latter to an extinct 

 species, with the name of Bison crassicornis, to render it probable that this may have 

 belonged to the same. 



In some respects the California fossil differs from either of the others mentioned. 

 The horn cores are proportionately less robust in comparison with their length, 

 and less abruptly tapering than in the original specimen o^ B. antiquus ; and they 

 are directed transversely outward instead of obliquely outward and backward, as is 

 represented to be the case in B. crassicornis. 



Comparative measurements of the fossil originally referred to Bison latifrons, (1), 

 that to B. antiquus (2), and the fossil Bison from California (3), with the measure- 

 ments of B. crassicornis (4), given by Richardson, in the Zoology of the Voyage of 

 the Herald, are as follow : 



Distance between tips of horn cores, 



Distance between bases of horn cores, 



Circumference at base of horn cores, 



Length of horn core along ujjper curvature, 



Breadth of forehead in front of cores where narrowest, 



Length of forehead from inion to fronto-nasal suture, 



Height of inion from lower margin of occipital foramen, 



Breadth of inion, .... 



Breadth of space occupied by condyles, . 



12 3 4 



Inches. Inches. Inches. Inches. 

 36 



16 15 Hi 



21 15 14J 12J 

 9i 



13 lOJ 



13i 9-7 



8 7 6 



13 



7 6 5-7 



CAPRIDJE. 



OVIBOS. 



Ovibos moschatus. 



Bos grunniens, Fabricius : Fauna Grcenlandica, 1780, 28. 



Musk Ox, Pennant: Arctic Zoology, 1792, 12. Buckland: Appendix to Beechey's Voyage, 1831, 



595, 606. Hayes : Open Polar Sea, 1867, 390. 

 Otibos moschatus, Kichardson : Zool. Voy. Herald, 1854, 22. Leidy : Proc. Ac. Nat, Sc. 1854, 



210. 



Remains at Eschscholtz Bay and Greenland. 



There are portions of four skulls of this species in the Museum of the Academy, 

 obtained by Dr. I. I. Hayes at Port Foulke, Greenland. All the specimens appear 



