690 SHUFELDT—OSTEOLOGY OF THE STRIGES. [Dee. 7, 
Elliptical articulating facets for the tubercula of the ribs, looking 
downward and outward, are seen on the inferior ends of the transverse 
processes, with a midridge running from each facet to the base of the 
process, to be expanded and lost on the sides of the centra. As there 
are five dorsal vertebrae, so there are five dorsal ribs articulating with 
them and with the sternal ribs below. Each rib is attached to a sin- 
gle vertebra, as shown while speaking of the dorsals. The neck of 
these ribs become more elongated the nearer they are to the pelvic 
extremity of the body, the first possessing the shortest. This is 
exactly reversed in regard to the pedicles bearing the tubercula, 
being the longest in the first rib and shortest in the last. This 
contraction of the pedicles is progressively compensated for by the 
lengthening of the corresponding and respective transverse pro- 
cesses of the vertebra to which they belong. Viewing the ribs from 
the front, in the skeleton, the curve they present resembles the 
quadrant of a shortened ellipse, the vertex of the major axis being 
situated at the base of the neural spines; viewed laterally, the curve 
is sigmoidal, though a much elongated and shallow one, with the 
hemapophysial extremity looking forward and the facet of the 
tubercle backward. The first rib is the shortest and generally, 
though not always, the broadest; the last being the longest and 
most slender, the intermediate ones regularly increasing in length 
and diminishing in breadth from the first to the last. In form, the 
ribs of this Owl are flattened from side to side, widest in the upper 
thirds, narrowest at their middles and club-shaped at their lower 
extremities, where they articulate with the sternal ribs by shallow 
facets. On the inner surfaces we find the necks produced upon the 
bodies as ridges, running near their anterior margins and becoming 
lost at about the junction of the upper and middle thirds in the 
body of the rib. Pneumatic foramina, from two to three in number 
and of considerable size, are found just within the commissure be- 
tween neck and tubercle, posteriorly. -All the vertebral ribs bear a 
movably articulated epif/eural appendage, each resting in a shallow 
cavity designed for it upon the posterior borders. They leave the 
rib at right angles, but soon turn upward with a varying abrupt- 
ness. The appendage of the first rib is situated lowest of any on its 
rib, that of the last the highest ; the facets of the others are found 
in the line joining those of the first and last. They all make acute’ 
angles with the bodies of the ribs to which each belong, above their 
points of insertion. The angle made by the last is the least, and it 
