\ 
1900.] SHUFELDT—OSTEOLOGY OF THE STRIGES. 693 
ward, disappears gradually with the groove it bounds. That por- 
tion of it from the point where it changes its direction to its ter- 
mination is described by authors as the subcostal ridge. The ma- 
nubrium, occupying its usual position in the middle line, is com- 
paratively small, quadrate in form, compressed below, slightly 
notched and flattened above, its posterior surface forming the inner 
anterior surface of the coracoidal groove. All the borders bounding 
the posterior parts of the bone are sharp ; the lateral ones, taken from 
the apices of the costal processes to their other and lower termina- 
tions, are concave. As is the arrangement generallyamong Owls, the 
xiphoidal extremity of the sternum is four-notched, two on either 
side, the outer notches being the deeper. Both have rounded 
bases, and the processes that separate them are ample and possess 
rounded extremities. The border upon which the keel ends poste- 
riorly is square, though we have met with specimens in which it was 
slightly notched in the median line. The body is oblong, and if 
we include the xiphoidal processes on either side, has a length half 
as long again as its width. The ventral and convex surface, like 
the dorsal, is smooth and presents but two points for examination. 
The pectoral ridge, faintly marked throughout its extent, originates 
on each side at a point near the outer borders of the coracoid 
grooves, running inward and backward, and dies away at the base 
of the keel near its middle. This little ridge denotes the line be- 
tween the pectoralis major and minor. The keel is moderately 
well developed, the distance from the base of the manubrium to the 
carinal angle being equal to the distance from the same point at 
the base of the manubrium to the base of either costal process or 
outer anterior sternal angle. It is compressed, smooth and thin, 
but its stability is greatly aided by the carinal ridge on either side, 
which commences strong and well-marked at the base of the manu- 
brium, just within the anterior border, running parallel with the 
latter, and disappears as it approaches the carinal angle. The ante- 
rior border of the keel is sharp and concave ; the inferior border 
is convex, with the edge slightly thickened. The point of inter- 
section of these two borders anteriorly is rounded and forms the 
carinal angle. The inferior border expands posteriorly, and the 
keel terminating a short distance before arriving at the posterior 
sternal border, the two become blended with the surface of the 
body of the bone. 
Sacral Vertebre and Coccygeal Vertebre.—In the sacrum of the 
