I O 2 Bulletin American Museum of Natural History. [ Vol. XVI , 



Genus ALLOPS Marsh. 



Syn. ? Diploclonus Marsh. 



Canines lanceolate, flattened posteriorly, incisors 7. Horns with 

 greatest diameter progressively transverse, pointed outwards and 

 forwards. 



The distinctness of this genus is doubtful. 



UPPER BEDS. 



AUops serotinus Marsh. — Superior premolars with small 

 postero-internal cusps (tetartocones). Represented by two 

 skulls in the National Museum, recorded from the Upper Beds. 

 No connecting crest between the horns. 



AUops crassicornis Marsh. — Type No. 4289, Nat. Mus. 

 Superior premolars with large postero-internal cusps ; cingula 



■^, 



Fig. 7. Diploclonus ampins (Marsh). (Yale Museum.) Type. X |. 



more prominent; zygomata with flattened buccal processes. 

 No connecting crest between the horns. 



AUops amplus Marsh. — Type in Yale Museum. Charac- 

 ters similar to the above with the exception of a strong 

 connecting crest between the horns and a pair of rugose 

 internal hornlets on the horns, hence the term ' Diplo- 

 clonus.' It is possible that this species descended from M. 



