O. C. Marsh—New Tertiary Mammals. 243 
In the present species the skull is of moderate length. The 
horn-cores are oval in outline, and placed ane opposite 
each other on the free portion of the nasals, a short distance 
back from the extremity. They are directed upward and out- 
ward, and their surface is rugose. e orbit is small, and 
ont 
T 
bones of the s erat indicate that ie were four 
digits in the a and three in the pes. 
Measurements. 
bai from front of first eer to end of Se 
yies, 456° ™m- 
sad ee ee ee 
Extent of upper oer NMR A ances gts 121 
Antero-posterior een of last upper molary.2.cc. + cus 41 
Transverse diamebinsscc os 4.oeva baie ness 5 
ntero pom 3 diameter of penultimate upper molar, .. 49° 
Tenneverse.. diametet 552 soc abl ow phe ee en on 55 
ria epg a Aca: of last upper premolar, -. ---- 35° 
Transverse diameter, ---- ---- 50° 
Anteré-posterior diameter of first upper premolar, ---- .. 25° 
Transverse diameter, -. << 2.2...) <n oe 
Width of palate between first upper srt ehen 43° 
Width between penultimate Bg ge lice WORT eee ce 69° 
Length of third accra eae. aes pen Ree 
idth of proximal en se 
Lene of first ancl of third digit of manus, . ep SE 31° 
Transverse oe OF anon a ee Oe 
Vestinal diametercs 02 cess a es eee 45° 
The known ait of the present species indicate an animal 
about two-thirds the size of the Indian Rhinoceros. They are 
jay the Miocene beds, near the John Day River, in Eastern 
reg 
Diceratherium nanum, sp. nov. 
A second species of the above Sane is Mose oaie by the 
greater part of a skull and teeth, and s other remains. 
These specimens pertai ne to an animal seek more than one- 
half the bulk of that last described. The horn-cores are more 
compressed, and the extremity of the — in front of them is 
inted. The anterior narial opening is la e premaxil- 
aries are slender and compressed. They do ae extend so far 
orward as the nasals. 
