— 
Sep. 19, 1872.] 469 {Cope. 
THIRD ACCOUNT OF NEW VERTEBRATA FROM THE BRIDGER 
EOCENE OF WYOMING TERRITORY. 
By Epwarp D. Corr. 
(Read before the American Philosophical Society, September 19, 1872.) 
SryPOLOPHUS INSECTIVORUS. Cope. Sp. nov. 
Represented by a posterior molar and a premolar of the right side of 
an animal less than half the size of the S. pungens, Cope. The molar 
presents three anterior trihedral acute tubercles, of which, one is exterior 
and more elevated than the others. Its posterior plane forms one trans- 
verse face with that of the inner posterior. The posterior tubercular 
heel is low, and supports an oblique ridge which bounds a deep groove 
behind the outer cusp, no doubt to receive that of the upper jaw. This 
arrangement is not seen in S. pungens. The premolar is a flat cone with 
faint traces of a tubercle behind and cingulum on inner side. 
M. 
Length crown molar. .... 26... eee e sere cence ener 0.0050 
Height immer cusp........ +22 s- esses sec e es eeeeseees 0040 
Length Reel... .. 6. eee se ese eer ess te te Scenes tes eee 0025 
WOU GLOW . ss ikets eee oie Usa oe tities Ve sie .0030 
Height crown premolar...........-. cece cece eee tenes 0040 
Length - BO aie tease ose asa eee wb 0040 
Found in the Eocene Bad Lands of Black’s Fork, by the writer, 
SryPOLOPHUS BREVICALCARATUS. Cope. Sp. nov. 
Established on a portion of the left mandibular ramus, containing the 
penultimate and ante-penultimate molars, of an animal of larger size 
than the type of the genus 8S. pungens. The molars have the general 
characters of the corresponding ones of that species, but differ in their 
greater elevation in comparison with their length, and the greater convexity 
of the outer side. The shortness is occasioned by the abbreviation of the 
heel, which in the last molar present, is very small and flat, without keel 
or tubercle on its surface. That of the molar preceding it is larger, 
and presents in its elevated outer margin, a trace of the keel seen in the 
smallest species. Enamel smooth. 
M. 
Length of two molars.....+. 666s esse eee cee eee eee ee 0.016 
fe ‘¢ penultimate Crown.............. ee eee eee .008 
Width = SORE ARR eR NAY CV UU Ea OW ee 0047 
Length ‘ < MOGlis Rhian eee Cees seat 002 
There is some relation between Stypolophus and T'riacodon, Marsh. If 
the heel of the molars of the former were wanting, they would be those 
of the latter. The premolars might be supposed to have this structure, 
but the form seen in S. insectivorus disproves this view. In fact, [ have 
seen both molars and premolars of Trtacodon aculeatus, Cope, and the 
former lack the heel of the Stypolophi entirely. 
