132 



Annals of the Carnegie Museum. 



The Vertebrae. 

 The Atlas. — In comparing the atlas with that of Diploceras osborni 

 Peterson,^ it is at once observed that the bone is proportionally higher 

 and longer, but of a less transverse diameter, which is due chiefly to 

 the shorter transverse process in the present genus. The anterior 

 cotyle is on the whole very nearly as large as, but is deeper than, in 

 Diploceras, and its inferior surface is more distinctly separated. The 



Fig. 4. Hyoid apparatus, i. Dolichorhinus longiceps (?), No. 2865; 2. 

 Tapirus terrestris, Yi nat. size, hh = basihyal, th = thyrohyal, ch = ceratohyal, 

 eh = epihyal, sh = stylohyal. 



odontoid process of the axis is proportionally longer and reaches nearly 

 through the inferior arch of the atlas, while in Diploceras it does not. 

 The articulation for the axis is much deeper than in Diploceras and 

 not nearly as broad, in this respect more nearly suggesting the condi- 

 tion found in some rhinoceroses {Diceratherium) than the horned 



'Ann. Carnegie Museum, Vol. IX, 1914, pp. 37-38. 



