THE OSTEOLOGY OF HYiENODON. 513 
peculiar sl.ape when viewed in profile from the front. Looked at in this way, it is 
seen to rise gradually from the suprascapular border, maintains a uniform height 
for most of Gs course, and then curves up {i. e., toward the external side, when the 
bone is in its natural position) to form the prominent and curious acromion. The 
latter is a compressed and plate-like projection, which extends externally and dis- 
tally, though not reaching or overhanging the glenoid cavity. There is no trace of 
a inetacromion, and the acromion is not in any way flattened, depressed or retro- 
verted ; it thus difl’ers very markedly from the type of structure found among the 
true Carnivora. Ihe spine, as a whole, is slightly recurved, which gives it a convex 
anterior and concave posterior face; distally it extends nearly to the glenoid cavity. 
Thii-httmerus is short and weak in proportion to the size of the animal ; aside 
from this it is distinctly canine in character. The head is relatively large and 
antero-posteriorly is nearly hemispherical, though much less 
strongly convex in the transverse direction ; it presents back- 
ward almost as much as proximally. The external tuberosity 
is high, rugose and massive, but does not extend across the 
entire anterior face of the bone. The internal tuberosity is 
small and laterally compressed, with a roughened face, while 
the bicipital groove is widely open and not very deeply in- 
cised. The proximal portion of the shaft is laterally com- 
pressed, but of great fore-and-aft depth; distally it contracts 
to an almost circular section, below which it is moderately ex- 
fr,‘insvpr.selv. The development of the deltoid ridge 
American aim rmroppan - 
served in many other parts of the s'ee on. 
