0. C. Marsh — Notice of New Fossil Mammals. 325 



Aceratherium actttum, sp. nov. 



Remains of the present species are abundant in one hori- 

 zon of the Pliocene east of the Rocky Mountains, and a large 

 number of fine specimens have been secured, which are now 



Pig. 3. 



Figure 3 — Skull of Aceratherium acutum, Marsh; seen from the left. 

 Figure 4. — The same specimen ; seen from below. 

 Both figures are one-fifth natural size. 



in New Haven. The skull represented above, in figures 3 and 

 4, has been selected as the type. It is narrow at the base, with 

 widely expanded zygomatic arches, and with the facial portion 



