PLATE XCIII 



Skulls of Beontops dispar 

 About one-fifth natural size. (See pp. 490, 492) 



A, Nat. Mus. 1217, skuU p {lAllops serotinus), Big Badlands (probably Indian Draw), S. Dak., Titanoiherium zone, level "some- 



what doubtful, probably lower C" (Hatcher). This very progressive skull shows certain of the characters common to Brontops, 

 Allops, and Menodus, in contrast with the Brontotherium-Megacerops group. 



B, Nat. Mus. 4941, skuU D, type. Hat Creek, Nebr., Titanoiherium zone, level middle B (Hatcher). This laterally crushed skull, 



the genotype of Brontops, was evidently brachycephalic, with stout rounded horns, thick nasals, short thick canines, and 

 heavy zygomata. The horns are well in front of the orbits. It is thus more or less intermediate in form between the highly 

 specialized B. robustus and the primitive B. brachycephalus and also exhibits convergent resemblance to the type of Brontothe- 

 rium tichoceras. 



