Cope.] 466 [Aug. 15, 
SECOND ACCOUNT OF NEW VERTEBRATA FROM THE 
BRIDGER EOCENE. 
By Epwarp D. Cops. 
(Read before the American Philosophical Society, August 15, 1872.) 
HELOTHERIUM PROCYONINUM. Cope. Spec. nov. 
This species is distinguished from those already known as pertaining 
to this genus, by its small size, as it did not much exceed the raccoon in 
dimensions. The size of a right superior molar is as follows: 
M. 
bengths 3... <i; Pia i NEAR Sin eT a ruber s Lateeacie y ly 37 01007, 
Width; posterior i cicad ov. Ne Te a sl Eawliats shies .0085 
ee BULELION ii. 0 5) s Os yon er ee ee ae pare ts OG 
The crown presents four tubercles, of which the inner are flat on the 
posterior, the outer flat on the external side. The posterior external has 
a small posterior supplementary lobe, and a low tubercle intervenes be- 
tween the two posterior. An anterior and a posteriorcingulum. Enamel 
smooth. 
STYPOLOPHUS PUNGENS. Cope. 
Gen. et spec. nov. 
This genus is supposed to embrace a small species of carnivorous ani- 
mal found by the writer in the Eocene formation of the Bridger Group. 
It is represented by the posterior portion of the left mandibular ramus, 
which contains the last two molars. 
The generic characters are seen in the composition of these molars, 
which have but two roots, and a posterior table, as is seen in tubercular 
molars of some mustelidw. The anterior two-thirds of the crown is com- 
posed of conic cusps. On the last molars these are in two series, two 
lower, of the inner, and one more elevated, of the outer, opposite the in- 
terval between the outer. Its outer face is regularly convex, but its 
posterior forms, with that of the outer series, a single flat vertical plane, 
which forms a sharp angle with the inner and outer faces of the cusps. 
The structure is, in general, somewhat like that of Mesonyx, Cope, but 
the lack of cutting edge on the posterior lobe, and the two rows of tuber- 
cles separates it at once. Dr. Leidy describes Stnopa as having a sec- 
torial tooth, as in ordinary Carnivora, with an interior cusp, hence it is 
not probably the present form, although this species was about the size 
of the 8. rapaw. 
The enamel is smooth. The measurements are : 
M. 
Depth ramus at last molar........ SON aoe es ors tvcse 0.014 
dgength lasthmolarss sist cei. ee Oe cee ne 0072 
Width He POBUCTIOLLY:s 416. ¥ sou lot Ure re .0040 
Height inner tubercle...... dV op MM Aas Bh hd ots eos ns .0062 
#f Sxtommals.“s(ANteniOl s.. i00 ia atest 4 tedie eve aaa 
This species was about the size of the gray fox. 
From the bluffs of Cottonwood Creek, Wyomin 
