DISCOVERY OF THE TITANOTHERES AND ORIGINAL DESCRIPTIONS 



233 



This animal stands nearest M. selwynianus, though dis- 

 tinguished by the greater size and slightly greater width 

 of the nasals. The sharp malar bridge is the most abso- 

 lute character. The two hornlets are possibly variations. 



Type locality and geologic horizon. — -Big Badlands 

 (probably Cheyenne River badlands), S. Dak.; 

 Chadron formation (TitanotJierium zone), exact level 

 not determined. 



FiGTjHE 195. — Type skull of Megacerops brachycephalus 

 Nat. Mus. 4261. One-fourth natural size. 



Etymology. — lis, twice; cornutus, horned; in allusion 

 to the presence of small accessory horn swellings. 



Present determination. — The species is probably 

 valid. 



Megacerops marshi Osborn, 1902 



Of. Allops marshi, this monograph, pages 511-515 



Original reference. — Am. Mus. Nat. Hist. Bull., vol. 

 16, pp. 100-101, fig. 6, 1902 (Osborn, 1902.208). 

 101959— 29— VOL 1-^18 



Type. — A complete skull (Am. Mus. 501). (See 

 fig. 197.) 



Paratype. — Skull (Am. Mus. 1445). Collected by 

 American Museum expedition, 1892. 



Specific characters. — Osborn writes: 



Type, skull No. 501; cotype, skull No. 1445, Am. Mus. 

 Nasals elongate and square distaUy, horns short, of oblique 

 oval basal section, overhanging the maxillae, or projecting 

 forward or outward. Incisors, ?f . Canines short, tetartocones 



