422 



TRANSACTIONS OF THE AMERICAN PHILOSOPHICAL SOCIETY 



the needle-gars (Fig. 289^^). As to the exceptions, in the engraulids (Fig. 40), morays 

 (Fig. S2B), gonostomids (Fig. 53), gastrostomoids (Fig. 56) and some others, the hyomandib- 

 ular has become much inclined backward in correlation with the backward displacement of 

 the quadrate-articular joint and the backward lengthening of the jaws. 



B 

 Chastodon 



A M icropterus 



Fig. 291. Adaptive radiation of jaws and teeth in percomorphs. 



The opposite case in which the suspensorium and the quadrate-articular joint are 

 produced very far forward is exemplified in the balistoids (Fig. 290). 



In the embryonic and larval stages of most teleosts the eyes are very large, the mouth 

 small and the suspensorium is curved forward beneath the eye. This arrangement in 



