SHUFELDT.] OSTEOLOGY OF THE CATHARTIDA. T79 
developed one on the vertebra next behind, in this Condor, added to the 
marked lateral compression of the centra of the first three or four sacral 
vertebra, give this bone an extremely odd appearance for its under and 
anterior half, the bone dipping far down into the abdominal cavity, a 
characteristic that is more or less evident among others of the family, 
but we do not find it soin Meophron, an Old World Vulture that pos- 
sesses a pelvis very much nearer the Falconide. Branches of the sacral 
nerves, the motor and sensitive roots, make their exit from the sides of 
several of the middle segments, the foramina being placed one above 
another, the largest apertures occurring in the mid-series, becoming 
smaller as we advance anteriorly or posteriorly. 
The margins of the anterior, and at the same time horizontal, portion 
of the iliac bones are quitesharp. They converge to points ata greater 
or less distance beyond the acetabula, depending upon the species, 
where they suddenly become robust and rounded and continuous with 
a similar surface belonging to the “heads” of the pubic elements, or 
that portion of these bones on either side which complete the cotyloid 
rings. Opposite this, the constricted portion of the pelvis, or rather its 
narrowest part, we observe the greatest amount of enlargement of the 
neural canal to accommodate the ventricular dilatation of the myelon; 
here, too, short parapophysial braces come from the vertebre, to be directed 
upwards, the anterior one abutting against the ilium on either side, the 
posterior rarely, if ever, meeting these bones. 
Viewing the under side of the bone, we note that it is just beyond this 
locality that we drop into what really may be designated as the “ basin 
of the avian pelvis,” and here usually the next three vertebre throw out 
only their superior processes as braces to the ossa innominata, while the 
last five (Pseudogryphus, Cathartes, Catharista) or six (Gyparchus) sacrals 
have.strong parapophyses that unite at their outer extremities with each 
other, and with the other processes coming from the vertebre all along 
the iliac borders on either side; of these, the first pair is the longest and 
are the ones opposite the cotyloid rings, the last two having all of their 
processes run more or less together, forming two pairs of strong rounded 
braces that are extended nearly horizontally to the “side bones.” This’ 
pelvic basin is very commodious and deep, more particularly in the Con- 
dors and the Carrion Crow; this condition is much enhanced by a sort — 
of reduplication that takes place-from the posterior and united portions 
of the ilia and ischia, forming a concave recess on either side just within 
the ischiadic foramen. 
Upon a lateral view of the pelvis, we find the acetabular ring pearly 
circular, the peripheries of the inner and outer boundaries coming nearest 
together in their upper and anterior arcs, while at their posterior and 
upper ares they form the outline of an extensive antitrochanter, whose 
surface is directed forwards, downwards, and outwards. The greatest 
amount of surface for the articulation of the femoral head, between the 
internal and external ring, is found anteriorly and below. A stout os- 
seous pillar separates the cotyloid ring from the much larger and sub- 
elliptical ischiadie vacuity, which is posterior to it. Below and between 
the two we find the long, oval obdurator foramen, its major axis nearly 
parallel with the pubic bone, and a deficiency occurring at its posterior 
are, where this latter element fails to meet the ischium. ‘The separating 
and. outlying bone about these lateral openings in the pelvis of the 
Cathartide is thick and strong, more particularly about the acetabular 
ring, affording ample support for the powerful pelvic limbof these birds. 
The pubic style, after passing the obdurator foramen, is a moderately 
wide strip of bone, compressed from side to side, nearly or quite touch- 
