1900.] SHUFELDT—OSTEOLOGY OF THE WOODPECKERS. 609 
In Sphyrapicus the xiphoidal processes are uncommonly slender ; 
the body of the bone thin and delicate ;' while the horns of the 
manubrium are a little larger again. 
All of our species of Woodpeckers possess an os humero- 
scapulare at either shoulder-joint. It has much the same form and 
relative size as we find it in birds of comparative proportions 
among the Passeres. With respect to the several bones of the 
shoulder-girdle, however, they are seen to have quite dissimiliar 
patterns among the /7c7, although the general plan or form is the 
same. Most curious do we find a scapula to be in Co/apées. It is 
fashioned like a flattened great J, with the curved portion enlarged 
and directed outward. Either coracoid has a long, slender shaft, 
with the head of the bone much produced upward, and compressed 
from side to side. At its sternal extremity we find a sharp, thin, 
hook-like process at its outer aspect, with two concave, transverse 
facets below, and a small subcircular one at its suprainterno-mesial 
angle. As we know, these facets are for articulation with the 
sternum. ‘The glenoid facet at the other end of the bone is long 
and narrow, and is inclined to be convex outward rather than a 
“‘cavity,’’ as it really is on the scapula. Os furcula is of the. 
typical U-shaped pattern, with enlarged, triangular, transversely 
compressed heads, and no hypocleidium below. The clavicular 
limbs are delicately constructed, and likewise compressed in the 
transverse direction. All the bones, with perhaps the exception of 
the furculum, of this arch are highly pneumatic, and when articu- 
lated zz situ the great, flattened, subtriangular head of the fur- 
culum on either side is lain flat against the scapula and coracoid, 
which in turn are articulated in the usual manner. 
Adult Ivory-billed Woodpeckers possess a strong pectoral arch, 
and in this species all of the bones composing it are thoroughly 
pneumatic. Relatively they are considerably shorter than the cor- 
responding bones in a Co/apées, with their extremities somewhat 
stouter. The scapula does not especially remind us of a J, al- 
though its posterior end is abruptly turned outward, but it is about 
at right angles with the shaft and not enlarged or curved any. 
Proportionately speaking, the coracoidal end of a scapula in this 
1 I have one specimen that shows a normal circular fenestra in it on the right 
side, just anterior to the inner notch, and probably this character will be 
found in a certain percentage of the sterna of this species, S. v. machadlis, as 
well as others of the genus, 
