U. S. GEOLOGICAL SURVEY 



MONOGRAPH 55 PLATE CVII 



NASOFRONTAL REGION OF SKULLS OF DIPLOCLONUS 



A, D. bicornutus, type (Am. Mus. 1476). B, D. tyleriO), referred (Am. Mus. 1081); 

 the nasals are largely reilored. C, D. tyleri, type (Amheril College Zool. CoU. 

 327; after LuU). In these skulls we observe a progressive enlargement and 

 widening of the horns, which culminates in D. amplus. (See pp. 501, 503, also 

 Pis. CIV, CV, and CVI) 



