PLATE CXLV 

 Skulls of Megacerops copei and M. bucco 



One-fourth natural size. (See pp. 543, 544, 548, also Pis. CXLIII and CXLIV) 



A, Megacerops copei, skull V, type (Nat. Mus. 4711), Indian Draw, Big Badlands, S. Dak., Chadron formation, level upper C 



(Hatcher). The skull is crushed laterally, thus concealing its brachycephaly. The premolars are in an advanced stage; 

 witness the large round postero-internal cusps and submolariform appearance of p*. The molars are very large, with large 

 protostyles and jutting hypocones. The canines are short and stumpy. 



B, Female skull referred to Megacerops bucco, skuU 0' (Nat. Mus. 4705), South Dakota, Titanotherium zone, upper levels of middle 



part (Hatcher). A very old supposed female. P* very progressive, with a large mesostyle; premolars with reduced internal 

 cingula; canines very small. Skull very brachy cephalic, zygomata widely expanded (unusual in females). 



