766 GEOLOGICAL SURVEY OF THE TERRITORIES. 
sooner do the fan-like lower ends commence to contract to merge intoa - 
shaft than dilatation immediately sets in again toform the great tuber- 
ous heads that constitute the opposite and superior extremities. More 
of a true shaft exists in Catharista than in any other of these Vultures, 
for the coracoids are proportionately 
longer in this species; in allitis more 
or less compressed from before, back- 
wards, rounded externally, sharper 
within, where in each boneit is pierced 
midway by an elliptical foramen, such 
as we found in Speotyto. This last 
feature is scarcely perceptible in the 
Carrion Crow. -In each the facet for 
the scapula is behind and rather to- 
wards the median plane; it is placed 
= . | \ _ transversely upon the bone, occupy- 
\ \\ ale ing the upper surtace of the scapular 
\ wef? process, and is continuous with the 
\\ i\ | shallow glenoidal facet that is seen 
\ ! on the outer aspect. The coracoids 
: j terminate superiorly in rounded 
i heads that are flattened from side to 
{r side, and present upon their mesial 
aspects smooth surfaces for the broad 
clavicular limbs. The blades of the 
scapule are short and broad, being 
curved outwards, with rounded 
points; they never reach back nearly 
so far as the pelvis, but generally 
overlap the last pair of dorsal ribs. 
The heads of these bones are flattened 
from above downwards, curled up on 
their inner aspects, so as to afford 
surface to articulate with the points 
of the eclavicular ends, while ex- 
e™ ternally they present raised elliptical 
/ facets that go to complete the glenoid 
cavities of each shoulder joint. The 
a entire anterior margin of a scapula 
Right coracoid of Pseudogryphus, viewed from in iS devoted to the articular facet for 
SOD CUED the coracoid. 
_ The glenoid cavity formed by the approximation of these two bones 
18 quite deep and extensive, and thus far we have failed to discover the 
presence of the os humero scapulare, and its assistance is apparently 
not in demand as an additional aid to retain the humeral head in the 
socket in these birds (Plate X VILI, fig. 108), the usual ligament being 
substituted for it. Our figures for the representation of the os furcato- 
rium show it to be the very type of the broad U-shaped variety or form 
(Plate XXIII, figs. 123 and 125, C. aura), and such it pre-eminently is. 
Superiorly this bone presents for examination the great flattened ends 
that articulate with the coracoids and scapule on either side; these 
are drawn out into rounded points behind to reach the latter, while a 
limited smooth surface on the outer aspect of either limb comes in con- 
tact with a similar surface on each of the former. All of the surface 
within the U is smooth and devoid of any points of particular interest. 
Without it, and above, in the expanded heads we find the entrances to 
