PECTORAL SKELETON OF TELEOSTEANS. Ba | 
The scapulo-coracoid is very little altered, and the whole 
of its anterior margin is applied to the slender spicular 
cleithrum. Its antero-ventral corner is much more prominent 
(pr. p.), and may with reserve be spoken of as a process. 
The postcoracoid process has attained astonishing propor- 
tions. It has rotated upwards. Its exact position is between 
the anterior portion of the trunk muscles and the skin (figs. 
13—14). It is evidently a structure of considerable import- 
ance, but in what way is difficult to tell. 
Stage IV (fig. 12).—The skeleton now bears a close 
resemblance to that of the adult, and, as in that, the scapulo- 
coracoid forms by far the greater portion. It is flat and 
plate-like, and stands in a vertical position comparable with 
that of the scapula in Stage IV of the salmon. The glenoid 
articulation has been formed by the breaking down of the 
cartilage. 
The tendency for the glenoid line to rotate from a nearly 
horizontal into a vertical position which we have followed 
through the earlier stages has now reached its consummation. 
The fin-plate has been perforated in three places prepara- 
tory to the formation of the four radials. 
The cartilage of the scapular region has extended dorsally 
and anteriorly with the result that its upper end is on alevel 
with the top corner of the fin skeleton. Its dorso-anterior 
border has been folded inwards and continued into a process 
(sc.’). A similar infolding was noted by Swirski in the pike. 
He cautiously suggested that it might be a relic of the meso- 
coracoid (p. 31). Ihave also seen it in the adult pike, and 
it seems to me more likely that it serves to supply a larger 
surface of contact with, and secures a firmer hold to, the 
cleithrum. 
The forward growth of the scapula has brought about the 
complete enclosure of the nerve, which up till now has run 
round its anterior border. 
The preecoracoid process is now more worthy of the name, 
though still very small as compared with that of the salmon. 
It has no relation to its fellow. The whole front border of 
