1900.] SHUFELDT—OSTEOLOGY OF THE WOODPECKERS. 607 
medio-submarginal foramen. One peculiar character is seen in 
this handsome Woodpecker, and it is in the first or anterior pair of 
its dorsal ribs. Here the epipleural appendages, the one on either 
side, fuse with the margin of the rib for the entire length of its 
superior border. In other words, the epipleural appendage is par- 
allel with its rib, its upper margin being codssified with the poste- 
rior or adjacent border of the rib to which it belongs. 
None of the species of the genus SAhyrapicus seem to present us 
with any very marked departures from what [ have attempted to 
give above in reference to their spinal column and ribs. They 
have s¢x free caudal vertebrz, the fenestra exists in the pygostyle, 
the atlas is perforated for the passage of the vertebral vessels on 
either side, and the ribs seem to be slenderer than is usual among 
Woodpeckers. 
In this genus, in JZ, carofinus and no doubt in some others, the 
lower ends of the last pair, or ‘‘ floating costal ribs,” codssify with 
the hinder margin of the costal rib in front of them. This is not 
the case in Dryobates, Picoides, nor in some others; it may occa- 
sionally be seen in the Pileated Woodpecker. 
Let us next consider the sternum in some of the Prcz. Several 
characters of this bone are held in common by all the repre- 
sentatives of the group. It is always found to be highly pneu- 
matic, with the foramina between the facets on the costal 
borders ; secondly, on the thoracic aspect (1) down the median 
line, (2) transversely within the anterior border, and (3) a large 
median one at the base of the manubrium. ‘The carina is com- 
paratively shallow, and notably extended forward beyond the body 
of the bone. Either costal process is lofty, pointed, with all the 
facets for the costal ribs arrayed down its posterior border. In 
front, a more or less bifurcated manubrium is seen. Behind, the 
body of the bone is expanded, and profoundly two-notched upon 
either side, thus giving the xiphoidal processes dilated posterior 
ends.* 
The costal grooves are prominent, separated mesially, and a 
small subcircular facet is found at the termination of either one of 
them externally. They are for articulation with the coracoids. 
1 In the sternum of a specimen of Colaptes mexicanus at my hand the inner 
notch of the left pair is a large subelliptical foramen, caused by the fusion of the 
inner tip of the process with the outer tip of the adjacent angle of the body of the 
bone. 
