214 MEMOIRS OF THE CARNEGIE MUSEUM 
available for comparison being Ictops dakotensis of the Oreodon Beds of the plains. 
Dr. Matthew found, in the same beds as the type, another specimen, which added 
a little to the features shown by the type. He gives more definitely the characters 
which are supposed to distinguish this from other known species.’ 
“Dimensions fifteen per cent. less than any of the Leptictide of the Oreodon Beds. 
First upper premolar one-rooted, two-rooted in I. dakotensis and bullatus and: Lep- 
tictis haydeni. Supra-temporal crests widely separated anteriorly and convergent 
posteriorly, instead of close together and parallel as in the latter species. Upper 
molars and P* more constricted between the inner and outer cusps than in any 
described Leptictid; cusps somewhat higher and last molar less reduced than in 
any later species.” 
With regard to the last character, I would say that I have the type specimen 
before me as I write, and the last upper molar is much smaller than M*, and much 
smaller than the one represented in Matthew’s illustration, fig. 4, in the paper from 
which I quote. 
Ictops Thompsoni Matthew. 
Bull. Amer. Mus. Nat. Hist., Vol. XIX., 1903, p. 207, fig. 5. 
This species was found in the same beds as IL. acutidens at Pipestone Springs. 
According to Matthew it is distinguished by the following characters : 
It is allied to L. acutidens but is smaller and has more compressed teeth. ‘‘ The 
metacone on all the molars is decidedly smaller than the paracene ; in J. acutidens 
they are nearly, and in other Leptictidee quite, equal in sizeon M+=. The protocenes 
on P+ and M® is more compressed antero-posteriorly, and the constriction between it 
and the outer cusps is more marked than in J. acutidens. The hypocene is smaller 
on Mt and M? and absent on M# and P*. The trittocene of P* is smaller than in 
TI. acutidens. All of these distinctions are exaggerations of the differences between 
I. acutidens and the Leptictidee of the Oreodon Beds.” 
Ictops montanus sp. nov. 
(Plate XXII., Figs. 1, 2, 3 and 4.) 
Carnegie Museum, No. 1020. 
From the Titanotherium Beds near McCarty’s Mountain, Montana. 
This is a finely preserved skull. It lacks the end of the snout, a portion of the 
brain-case, and the zygomatic arch on one side. 
PRINCIPAL CHARACTERS. — Skull quite broad and heavy behind with fairly large 
brain case. In front of the orbits a gradual constriction from all sides to form the rather 
1 Bull. Amer. Mus. Nat. Hist., Vol. XIX., p. 205. 
