32 
PI. VIII. A muscular ridge and rough surface (ib. fig. 9, r) mark the back part 
below the middle of the shaft. The bone then expands to its upper articular end, 
which is obliquely truncate from within outward : it shows, first, the oblong surface 
for the scapula, which is extended upon the inner prominence of that end ; next, the 
larger and full oval surface for the humerus (h), from which the thick, obtuse, inner 
continuation of the scapular end projects inward, forward, with a slightly upward curve, 
and shows the narrow oblong surface for the articulation and ultimate confiuence of the 
clavicle (58). The coracoid unites with the scapula at an angle of 100°. 
The clavicle (ib. figs. 4 & 5, 68), at its scapular end, is slightly expanded, compressed, 
with an obtuse recurved termination articulating with the above-named surface of the 
coracoid, and in one instance coalescing therewith, and by extended ossification with the 
“ acromion scapulse” (ib. figs. 8 & 9). As the clavicle descends it curves slightly and 
contracts to a point. The angle at which the pair meet is shown in figs. 4 & 5. 
Bones of the Wing. (Pis. III. & VIII. figs. 12-17.) 
Of the humerus the series contains two specimens, both measuring 4 inches 3 lines in 
length, one right, and the other left (PI. VIII. figs. 12-14), but differing slightly in their 
proportions and in colour — one being of the olive-brown tint with which most of the 
bones are stained, the other black. The articular head (ib. a) is an elongate oval con- 
vexity, with the larger end toward the radial side, prominent toward the back and rather 
flattened toward the front of the bone, which there swells out beyond the base of the 
articular surface. The radial tubercle is small, and descends from the radial end of the 
head for about 5 lines; the pectoral process (ib. b) is triangular, obtuse, short, and 
bent, or directed toward the front side of the bone : the ulnar tuberosity (ib. c) is more 
produced in that direction ; it is oblong, obtuse, with its base impressed by a large pit 
both above (fig. 12, h) and below — the lower one (ib. g) being the deepest, and perforated 
by a pneumatic foramen ; the convex, broad, ulnar border of this tuberosity has two 
slightly produced processes, an upper or posterior (ib. fig. 12, c) and a lower and internal 
(ib. g), which is the smallest. The breadth of the proximal end of the humerus, across 
the tuberosities, is 1 inch 5 lines, beyond them the bone contracts to a smooth subcylin- 
drical shaft, showing at the back part of the proximal third a longitudinal ridge (fig. 12, r), 
half an inch in length; it gradually expands at the distal third to a breadth of 10 lines, 
where the articulations offer the usual avian characteristics of the elbow-joint. The 
head of the humerus is occupied by a fine cancellous structure : into the large vacuity 
below this, crossed in the section figured (PI. XI. fig. 5) by a transverse slender bar 
of bone, the small pneumatic foramina at the bottom of the wide and deep fossa for the 
axillary air-cell open. The part of the hollow proximal end giving off the pectoral 
and other processes for the attachment of muscles is strengthened by similar abutments. 
The pneumatic cavity of the main part of the shaft of the humerus is simple, with a 
compact wall thicker than at the ends of the humerus, but not exceeding that which is 
