ON THE OSTEOLOGY OF NYCTOSAURUS. I41 
he calls doubtfully a pneumatic foramen. Whether the part is an acro- 
mion process of the scapula, or possibly a vestigial clavicle, must be left 
for future research. | 
The coracoid has a flattened shaft, oval in cross-section near its middle, 
and flattened at either extremity. The sternal articular surface is convex 
in its greater diameter, gently concave in the opposite direction. Near 
the outer extremity of the shaft, on the inferior border, there is a strong 
process, gradually arising from the shaft but with a deep concavity be- 
tween it and the articular rim. A small sesamoid ossicle was found 
lying near it. The shaft at its middle is narrowed and smooth; it seems 
to lack the strong muscular rugosity on the external part which occurs in 
the Pzteranodon coracoid; the process on the outer inferior border is also 
larger than in /¢eranodon. It will be observed also in the figure that 
the glenoid articular surface does not extend to the inferior margin of the 
coracoid, resembling in this respect somewhat the European forms of this 
bone. The scapula of course differs markedly from that of Pteranodon 
in the non-articular distal end. 
MEASUREMENTS OF CORACO-SCAPULA. 
Seer co -steriial articulation ._-- ¢..- ---o-464 sos ek 10 
en semmadti Ol shatt, below middie of coracoid._._.-.-_-----.-.---------_-- 7 
I OP ee ee ee en ns Lee oi ee 55 
een eriecia mercer, of olenoid surface... 2.22 ---- ~-----2.---+----- 19 
Id) ee es ae G2 ee i ee 49 
ERO TES Hatt) SCADUId 4a. sess de es eee ee 14 
Ee ree Ye tit¥ see ys ee on 16 
Humerus. Pl. XLII, Fig. 7. The humeri both lie with the inner 
side uppermost. The proximal articular surface is distinctly saddle- 
shaped, the convexity directed from behind forward and inward. The 
curve of the concavity is greater than that of the convexity in the speci- 
men. The ulnar or median process is very stout, reaching as high 
as the articular surface. It is broad above, with apparently two faces 
for muscular attachment, separated by a narrow, free space. Its rounded 
distal border sinks into the surface of the shaft at about its middle 
third. The deltoid, radial, or lateral process is very large. It is directed 
forward and a little downward, its lower margin uniting with the shaft 
at about the middle third. Both upper and lower borders are deeply 
concave, the upper one the longer. Its distal extremity is expanded, 
and has an evenly convex border from above downward. Near the 
upper end of this border, on the inner side, there is a small, oval, 
oblique surface, looking inward, for muscular attachment; and, begin- 
ning near the middle of the upper border, there is a slender, but well- 
