E. L. Troxell — Ccenopus, the Ancestral Rhinoceros. 45 



of C. copei. Other distinctive features consist of the 

 small ridge in front of the protoloph and the great 

 extension of the ectoloph forward on P^ the reduced 

 tetartocone of P^ and its union through a broad ridge with 

 the deuterocone, the strong deuterocone of P^ and more 

 especially of P^, and the weak metaloph which on P* is a 

 thin band so narrow that a wide space is left in front and 

 behind it for the deep fossae. 



Fig. 1. — Ccenopus tngonodus alius, subsp. nov. 

 skull. X 1/3. 



Holotype. Side view of 



The cingula are weak around the bases of the deutero- 

 cones, but on the molars the cingula are discontinuous 

 across the bases of the protocones and hypocones. Irreg- 

 ular tubercles and ridges obstruct the entrance to the 

 medifossette or central valley. There are no sharp sec- 

 ondary folds on the molars^ but the antecrochet is 

 prominent. 



(® 



Fig. 2, — Ccenopus trigonodus alius, subsp. nov. Holotype. Molar-pre- 

 skuU. X 1/3- 



P'^ are present, but the third incisor and the upper 

 canine are obsolete. The nasals are smooth, slightly 

 expanded over P^ and notched. There is a broad, shal- 

 low depression in front of the orbit. 



The specimen is from layers later geologically than C. 

 trigonodus but about the same age as C. copei. 



