220 MEMOIRS OF THE CARNEGIE MUSEUM 
In the upper jaw there is a short interval between the canine and P+, a quite long 
one between Pi and P2, and ‘a short one between P2 and P32. The mandible is 
deepest at My. The anterior ridge of the ascending ramus is heavier and broader 
than in J. intermedius. All the mandibles of the different specimens have two 
mental foramina; but, as will beseen by the illustrations, they have a little different 
position in each. 
Skeleton. — Nearly a whole ulna and the lower part of the radius are preserved 
They were apparently nearly equal in size. The radius is nearly 4 cm. in length. 
The olecranon is .8 em. There is a longitudinal convexity on the shaft of the ulna 
giving the bone an angulate appearance. 
One of the anterior dorsal vertebrxe is preserved. It has a long spine, which is 
very much inclined backward. 
Icrors. 
Carnegie Museum specimen, No. 812. 
This is the larger portion of a skull but it is much crushed and distorted so that 
but few of its characters can be definitely ascertained. 
This skull was found in beds of sandy clay west of Three Forks, Montana, asso- 
ciated with Titanotheriwm and a little Oreodont. The beds are different lithologically 
from those of the same region in which Limmnenetes platyceps, L. anceps, Agriochawrus 
minimus, Trigenicus socialis, Mesohippus latidens and associated Titanotheriwm remains 
were found. It is uncertain whether these beds are exactly contemporaneous with 
those containing the Jctops skull or not, but they must be nearly so. This skull 
is quite robust. The zygomatic arch is heavier than in any other specimen in the 
collection. The post-glenoid process is fairly long. The most noticeable feature is 
the wide interval which separated the supra-temporal ridges. They converge back- 
ward to within .6 cm. of the crest of the occiput and back of this diverge, becoming 
continuous with the lambdoid ridges. Where nearest they are 1 cm. apart. The 
occiput was broad, the nasals slender. 
Ictops Major sp. nov. 
Carnegie Museum specimen, No. 1022. 
Of this specimen we have the upper dentition back of P2, a large portion of the 
mandible with all the lower teeth except Iz, parts of the dorsal vertebree, the 
sacrum, part of the pelvis, portions of the tibiee, two caudal vertebre, two phalanges, 
and other small fragments of the skeleton. The specimens were found in the 
Titanotherium Beds southeast of McCarty’s Mountain, but at a lower level than the 
specimens above described. This represents the largest Ictops found in the beds at 
