1881,] 389 
[Cope. 
Measurements of Fore Limb. M. 
Length of Wi ars, sais sic ccs acdacidue getaentws este vs sans .010 
Depth I: i sede in moareunes ean ae alas a aueeaaniuit hie weed O11 
Length of magnum..............ecec cee e cee cee ee ees 005 
Depth Ret”, Sve Aa ce Medicus hue nine wet ena eines 017 
Length unciform............0ccc cscs cece ceecneeeceees .009 
Width WE GecatiSana acess Gag alayetaeidlalearemmiogs ae suleas ves 009 
Depth €s (tOtH)) cy ornate eiddcqeiassoeessee -014 
te se of inferior facets.................00005 007 
Length of third metacarpal........eceesseeeee seavees .068 
Proximal diameter third metacarpal { anteroposterior... .008 
transverse....... 008 
Length of fifth metacarpal.............0.0 cece cece cues 012 
ne median series of phalanges............00.005 027 
a first median phalange.................00008- -010 
Width of do. proximally...........c ccc cece eee e ees .008 
Length of second phalange...............0ceee sees eees .006 
proximally ...... .0070 
Widths of median ungual phalange Yea ieeebgg te 0055 
greatest.......... 007 
The body of this animal was about the size of that ofa red fox. The 
legs were more slender or elevated, and the head of course was shorter and 
thick. 
The unique specimen on which our knowledge of this species rests was 
cut from a block of calcareous sandstone of the bed of the Washakie basin 
of the Bridger Epoch, near South Bitter creek, Wyoming Territory. The 
bones are generally in the relation of the position in which the animal died. 
The neck is depressed and the left fore leg raised so as to be in contact 
with it, and the head is raised so as to clear the left wrist. 
TRIPLOPUS AMARORUM Cope. 
The characters of the fore-foot of this species being unknown, it is not 
possible to determine its generic position. It has, however, one of the 
well-marked characteristics of the genus Triplopus, in the osseous enclo- 
sure of the meatus auditorius externus, through the ossification of the ex- 
ternal prolongation of the otic bulla, and tympanic cartilage. I cannot 
therefore refer it to Hyrachyus. 
It is represented by a skull from which a large part of both maxillary 
bones and the mandible have been lost, and which is accompanied by parts 
of the ulna and radius, parts of the ilium, a femur, and tibia, and nearly 
all of the posterior foot of the right side. The posterior parts of both max- 
illary bones remain, and they support each, the last superior molar tooth 
from which the external wall has been broken away. The portions of 
molars remaining exhibit characters which lead me to suspect that the 
