698 SHUFELDT—OSTEOLOGY OF THE STRIGES. (Dee. 7, 
The pleurapophyses and parapophyses are very rudimentary or 
entirely suppressed. Each vertebra bears a prominent neural 
spine, which, from the first to the sixth, inclusive, is bifurcated ; 
in the last two it appears as a mere primitive knobule. The trans- 
verse processes are all deflected downward and outward, very 
small in the first and still more so in the last; are largest in the 
fifth and sixth. Prezygapophyses are well marked ; they reach for- 
ward and articulate with the feebly developed postzygapophyses. 
In a few of the posterior segments there appears to be an effort on 
the part of the neurapophyses to overlap the vertebra next beyond 
them. The neural canal is pervious throughout, commencing in 
the first with a calibre equal to that in the end of the sacrum; it 
gradually diminishes and terminates in a minute, blind conical 
socket in the pygostyle. Hypapophyses are produced downward 
in a few of the ultimate vertebrae. They hook forward and articu- 
late with the centrum of the vertebra next beyond them. Some- 
times they are observed to be free, or rather resting upon a facette 
on the anterior margin of one centrum and extending over to the 
anterior margin of the centrum of the vertebra anterior to it, to 
meet a similar facette, as a tiny styliform process. The spinal col- 
umn is completed posteriorly by the pygostyle—that ploughshare- 
shaped segment that articulates with the last coccygeal vertebra. 
Above its cup-shaped facet this bone arises as a laterally com- 
pressed plate, extending backward and bifurcated at its extremity, 
as if to imitate the neural spines of the vertebrz of the series of 
which it is an ultimate appendage. Below the facet it projects 
forward and completes the median sequence of hypapophyses of 
the centra, being rather larger than any of them. ‘The posterior 
curve is simply inflected downward and forward from its apex. 
The Scapular Arch.—The three elements that constitute this 
arch are all represented, and all independent or free bones; the 
coracoids articulate with the sternum and scapulz ;, coracoids and 
clavicle, connected by ligaments, lend their share to form or 
strengthen the shoulder-joints. The coracoid, comparatively large 
and strong, forms in the usual manner an arthrodial joint of 
restricted movement with the sternum, its lower end being in the 
coracoid groove on the anterior part of that bone. The inner 
angle of its base is about two millimetres from the mesial line, and 
four millimetres intervening between it and its fellow of the oppo- 
site side in the groove. This extremity is broad, its outer angle 
