PLATE CXXI 



Type Skull of Allops crassicornis 



Plate prepared under the direction of Professor Marsh. One-fourth natural size. (See p. 517) 



Nat. Mus. 4289, skull Z', type, Big Badlands, S. Dak., Chadron formation, level lower C. A photograph of the specimen as it 

 actually appears in the crushed condition is shown in Plate CXX, A. The aspect of the skull in this plate illustrates the 

 mingling of Brontops and Menodus characters seen in this genus. 



