SHUFELDT. | . OSTEOLOGY OF THE CATHARTID. 737 
In the cervical portion of the column one or more of these little aper- 
tures are found to pierce the centrum of each vertebra, within the ver- 
tebral canal or just outside of it, anteriorly. Thisis not a circumstance, 
however, we will find when we come to examine the dorsal segments, for 
here about the bases of the diapophyses or transverse processes great 
circular openings occur that allow one a view directly through the ver- 
tebra, and the center of these segments are in some cases riddled with 
similar though smaller foramina. Such openings, likewise, are found to 
exist at the inferior aspects at the extremities of the diapophyses, and 
sometimes a few minute ones in the metapophysial off-shoots beneath. 
The position of these foramina are but little changed, much less their 
number or size materially decreased or diminished in those vertebre 
constituting the sacrum. After we pass the first three or four seements 
of this division in C. aura, however, we seem to lose sight of them in 
the diapophyses, which is not the case among the species of the other 
genera, though they are very sparsely distributed in C. atrata. Arriv- 
ing at the coccygeal vertebre, we find that pneumatic foramina have 
disappeared entirely, and this holds good for all the Vultures and ap- 
plies equally well to the ultimate segment of this division, the pygo- 
style. We present two or three figures in which the extensive pneu- 
matic openings that occur on the outer aspects of the expanded heads 
of the clavicles may be seen. In C. atrata, as in the others, these con- 
sist essentially, one each side, of a large cloaca that extends immedi- 
ately into the bone, rendering it one of the lightest for its size of any 
of the skeleton. About the entrance of this general opening we observe 
many smaller and circular or variously shaped ones irregularly arranged 
in groups, with sometimes only a single one beyond, isolated from the 
rest (Pseudogryphus), or another separate little collection in this situa- 
tion (C. aura). In the scapula the openings occur near the glenoid cavity, 
and again a grouplet beneath the ridge found at the crest of the acromial 
process, on its outer aspect, but the number or size of these foramina in 
this bone is never very great. 
In any member of the family, a careful search about the head of either 
coracoid is usually rewarded by the discovery of a few scattered open- 
ings of this sort, but these bones seem to depend almost entirely for the 
admission of air into their shafts and extremities upon a cluster of 
these foramina that are met in the recess of the dilated ends below, on 
their posterior aspects. 
Passing next to the sternum, we find in all the Vultures, less marked 
in C. atrata than any, a rounded and prominent ridge, extending back- 
wards from the anterior margin immediately posterior to the manubrial 
eminence, to the middle line of the concave and superior aspect of the 
body below. It is on either side of this ridge that we find pneumatic 
perforations that lead into the heavier portions of the bone, more particu- 
larly the promintory of the manubrium, and downwards into the thick- 
ened carinal ridge. Again, in the recesses above the subcostal ridges 
we discover irregular groups of these pneumatic foramina, that pass into 
the lateral portions of this bone; while lastly, the apertures through 
which additional erification of the sternum takes place occur in the 
pits along the upper side of the costal borders, that we find among the 
facets of articulation for the sternal ribs. In these localities they have 
a tendency to gather around the bases of the eminences that support 
these facets, rather than be generally distributed throughout the depres- 
sions in question. (Plate XVII. fig. 107, Pseudogryphus.) 
In the free ribs, both those of the cervical division of the column, as 
well as the dorsal ones, we find these pneumatic foramina entering the 
47 H 
