THE SKTTLL. 



21 



In the t3q)e of Uinfatheriiini, tin's process appears to he nearly obsolete. 

 In front of this process is the snture uniting- tlie ex-occipital directly with 

 the squamosal, thus excluding- tlio mastoid tVoin the external surface of 

 the skull, as in Rhinoceros. The tympanic portion of the periotic, also, 

 does not reach the external surface. 



FiGUEE ]9. — Side view of skull of Tinoceras pugn xx, Marsh (Xo. 104-1). 

 Figure 20. — Anterior pyt of skiiU of Tinoceras grande, Marsh (No. 1040). 

 FiGl'RE '21. — Anlerior part of skull of Tinoceras annectens. Marsh (No. 1043). 



?n'. maxillary protuberance; me. estoranl ftuditory meatus; n'. nasal protuberance; o. occipital condyle; 



)•'. iiarietal protuberance: pm. premaxillary bone; pii. prcnasal ossicle. 

 All the figures are oue-elsrlitli nitural size. 



