are H. H. SWINNERTON. 
the girdle from the tip of the scapula to the end of the pro- 
cess is in the closest contact with the cleithrum, thus furnishing 
a striking contrast to the state of affairs in the salmon. 
Perhaps the most interesting feature at this stage is the 
ossification of the still very long postcoracoid process. This 
extends later to the coracoid region, thus giving rise to the 
bone of that name. 
Close to, but by no means continuous with, the postcoracoid 
process, is the * interclavicle ” (v. cl.), which is a true dermal 
bone as opposed to the coracoid which, as development shows, 
is a cartilage bone. 
The Adult.—The pectoral skeleton of the adult has been 
accurately described by Parker. It differs from that of 
Stage IV in the much greater extension of the scapulo-cora- 
coid in an antero-posterior direction. Also the scapula has 
risen high above the fin skeleton, and the foramen has become 
extraordinarily large. 
The “interclavicle” is now completely co-ossified with the 
coracoid. 
GENERAL CONSIDERATIONS. 
The Postcoracoid Process. 
This process was first seen and described by Swirski in the 
development of the pike. In that fish it is the most striking 
feature of the earlier stages, and remains prominent until a 
fairly late stage. By comparison with Silurus and through 
that with sturgeon he came to regard it as homologous with 
Gegenbaur’s “third process,” and Parker’s “ coracoid.” 
Wiedersheim found it also in developmental stages of grayling, 
catfish, and pike, and called it ‘‘ processus posticus.” He 
absolutely disagreed with Swirski in his interpretation, be- 
cause the process was directed caudally, and ran parallel to 
the long axis of the body. He also examined larve of the 
sturgeon, and not finding it in these he regarded it as a new 
structure peculiar to the Teleosts, developed for purposes of 
fixing and support (p. 170). Ducret found it also in the 
salmon, and called it “ processus ensiformis.” 
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