SHUFELDT.] OSTEOLOGY OF THE CATHARTIDZ. 759 
pressed at their middles and quite deep—this does not seem, however, 
to influence the form of the neural tube in this region to any great ex- 
tent, as jt remains almost uniformly circular throughout, markedly so 
in C. aura. Piercings into this passage on either side for the exit. of 
the dorsal nerves are made at the expense of certain parts, both before 
and behind, in each vertebra, giving rise to rather small irregular open- 
ings for this purpose. At the base of the transverse processes of the 
dorsal vertebrae, and again at their extremities, semi-circular facets 
exist for the capitula and tubercula of the dorsal ribs. Those at the 
bases are upon slightly raised elevations and look almost directly out- 
wards, those at the extremities look downwards and outwards, in awra 
and airata, but in S. gryphus and the California Condor almost directly 
outwards, especially in the last dorsal. 
The diapophyses become progressively longer as we near the sacrum, 
at the same time more inclined upwards; they are compressed from 
above downwards, being dilated at their outward extremities, where 
they bear distinct and styliform connecting metapophyses, the last pair 
being extended to the pelvis in Cathartes. 
Close and mutual locking is accomplished in this region, principally 
by a shortening of the pre- and postzygapophyses, the facets upon the 
former facing upwards and slightly inwards, upon the latter down- 
wards and slightly outwards, so as to be nicely approximated in the 
articulated skeleton. 
Sharpened ridges beneath the transverse processes connect the facets 
for the capitula and tubercula of the ribs; this feature is best marked 
in C. aura and next in G. papa, less so in the others. 
Vertically elongated but shallow depressions occur above the centra 
on the anterior and posterior margins of the neural spines, for the in- 
sertion of the broad connecting ligaments; the spines themselves spring 
almost abruptly from the neurapophysial arch, are uniformly quadrate 
plates of an equal height, with thickened crests above, that become 
united at their anterior and posterior ends by a modified arrow-head 
joint, such as we described in Speotyto, where the points were more 
acute. 
Mr. Lueas tells us, in the same communication cited above, that he 
found five dorsals in the spinal column of Vultur cinerea aud Gyps ben- 
galensis, six in Otogyps calvus. 
Owen clearly defines the condition of the hypapophyses in some of 
the Old World Vultures in the following words: 
From some or most of the dorsal centrums inferior processes (hypapophyses) are 
sent down, for extension and favourable origin of the flexor muscles, longi colli and recti 
antici, of theneck. In a Vulture (Gyps fulvus) the hypapophysis is a low median ridge 
in the first and second dorsals; to this, in the third dorsal, is added a pair of outstand- 
ing depressed plates; in the fourth the pair of plates are smaller, and, with the medial 
ridge, are supported on a common stem ; in the fifth dorsal the hypapophysis is again 
reduced to a median compressed plate, but it is expanded at the end; the vertebra, 
which by anchvlosis has become the foremost sacral, has a similar but stronger and 
slightly bifureate hypapophysis. In both Vultures and Eagles the parial hypapophyses 
are seen to be dueto modified parapophyses, which descend and are progressively lost 
in the median hypapophysis of the fourth and fifth dorsals (Harpeya, Cuv.); the sixth 
and seventh have only the low median ridge. (Anat. Verts. vol. IL, p. 17.) 
The caudal vertebre are very much modified, as they are as a rule, 
throughout the class; the number possessed by each species has already 
been given in one of the tables accompanying this monograph. They 
are considered next in order after the dorsals, as the author believes, 
and the reader will surely agree with him, that in the present subject 
