140 FIELD CoLUMBIAN MusEuM—GEOLOGY, VOL. II. 
the weight of the right arm lying across the body. ‘The presternal 
process extends about half an inch in front of the notarium. 
MEASUREMENTS OF STERNUM. 
mm 
Length in'middle ..--4, - ten 6 -cnl mete oe no th ean e ean ee 88 
Greatest width, across attachments of first rib_.-.-_-_-2 2 ee 80 . 
Length of rib marginS=._ 2-222-225-2222. a ee 3 oe 
Width at coracoidal articulations.2--_--— 4. 2 2 a 40 
Length of presternal process in front of coracoids--.----------- Pp ee. 16 
Width of xiphisternal proceéss-<ss~.---- 1222. 2-2. 0552 
Length of xiphisternal) process.-.- --22 0 2 ot II 
Coraco-scapula, Pl. XLIII, Fig. 6. This conjoined element is a mod- 
erately stout, U-shaped bone, with the coracoid branch stouter and a little 
longer than the scapular. The distal extremity of the scapula is slightly 
expanded and flattened spatulate; the shaft is flattened and somewhat 
constricted in width. ‘There is a rounded protuberance on the outer or 
upper margin, just beyond the glenoid rim, for the attachment of muscles. 
This process appears to be wanting in the specimen previously described 
by me of this genus, but it is possible its absence is due to some 
postmortem compression. The glenoid articulation is deeply concave 
from above downward, convex from side to side, and is bounded both 
above and below by a prominent ridge, that on the inferior border being 
much stronger than the upper one. The glenoid surface is placed 
obliquely to the shaft of the bones, doubtless in life looking outward 
and somewhat backward. The surface, from side to side, is narrower 
below than above. A line indicating the sutural union of the two bones 
passes directly through the middle of the articular surface transversely. 
At the bottom of the U formed by the conjoined bones there is a 
process, rather slender, arising from the inner surface of the scapula, 
and reaching to the inner face of the coracoid, which it joins. It incloses 
a small foramen between it and the-coracoid, back of and below the 
glenoid surface. <A precisely similar process is found in the coraco- 
scapula of Preranodon, and in neither genus does the suture dividing the 
coracoid from the scapula cross this process; it is, apparently without 
doubt, either a separate ossification joined to the two bones, or else a 
process from the scapula. I cannot at present examine the under sur- 
face of this scapula, and have none of /reranodon for comparison. In 
WV yctosaurus, however, the process seems to be separated from the scapula 
throughout a large part of its extent. If it really belongs with the scapula, 
the inclosed foramen cannot be the usual supracoracoid foramen of the 
reptilian coracoid. 
A similar foramen, though of larger size, is shown by Owen in the 
coraco-scapula of Ornithochetrus sedgwicki (Paleontograph., 1857), which 
