298 THE OSTEOLOGY OF ELOTHERIUM. 
The scapula is remarkably high, narrow and slender, at least in the White River 
species, while in the John Day forms there is reason to believe that its proportions are 
quite different. The glenoid cayity forms a narrow, elongate oval, with its long axis 
directed antero-posteriorly, and is not very deeply concave. The coracoid is a large, but 
not very conspicuous rugosity, which sends off from its inner side a compressed, hook-lhke 
process ; when the shoulder-blade is seen from the external side, this process is concealed 
from yiew. ‘The neck of the scapula is broad and rather thick, and there is no distinct 
coraco-scapular notch. The coracoid border in its upward course inclines forward but 
little, and for the upper one-third of its height curves gently backward, to join the 
suprascapular border, which is exceedingly short. The glenoid border is more oblique, 
and inclines backward and upward at a moderate angle. The spine is shifted far forward, 
dividing the blade very unequally, so that the prescapular fossa is very much smaller 
than the postscapular. Indeed, the distal one-third of the shoulder-blade can hardly be 
said to have any prescapular fossa at all. The spine itself is rather low, and for much of 
its course its free border is curved backward and thickened to form a massive meta- 
cromion. ‘The acromion is very short and inconspicuous, ending considerably above the 
level of the glenoid cavity. . 
The scapula associated with the large species of Elotheriwm from the John Day 
beds, which Cope has described under the name of Bodcherus (79, p. 59), is very 
different in shape from that of /. ingens from the White River, to which the description 
in the preceding paragraph more particularly applies. The blade is very much broader, 
both fossee widening rapidly toward the dorsal end; these fossee are of nearly equal width 
and the spine is placed almost in the middle of the blade. There can be little doubt that 
this scapula is properly referred to the incomplete skeleton with which it was found 
associated. Aside from its similarity in color and texture to the rest of the skeleton, 
there is no other amimal known from the John Day horizon to which so large a scapula 
could belong. 
The shoulder-blade of Hippopotamus is much broader, in proportion to its height, 
than that of /. ingens ; the coracoid is more prominent and the coraco-scapular notch is 
distinctly marked; the postscapular fossa is somewhat larger than the prescapular, but 
the difference is much less extreme than in the White River species, the spine occupying 
a more median position ; the acromion is much the same in the two forms, but the meta- 
cromion is larger in the fossil. In Sus also the scapula is relatively broader than in 
E. ingens, and, in particular, it has a wider prescapular fossa, but is without any distinct 
coraco-scapular notch. The spine rises from the suprascapular border yery steeply to 
the high (but much smaller) metacromion, and then descends gradually to the neck, 
without forming an acromion. In spite of these differences, the resemblance in the 
character of the scapula between Sus and Hlotherium is unmistakable. 
