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TRANSACTIONS OF THE AMERICAN PHILOSOPHICAL SOCIETY 



dubitably nearer to the primitive percomorph type than are the highly peculiar scombroids, 

 also that Coryphcena, although clearly allied with the carangids in skull structure, has the 

 vertebral and rib characters more or less transitional to the scombroid type. 



pmx 



Trachinottis falcatus 



Fig. 178. Trachinotus falcatus. 



Turning now to the skulls (Figs. 178-181), all carangids have a conspicuous extension 

 of the sagittal crest from the supraoccipital to the frontal, which is higher and more steep 

 in the more primitive compressed types and lower and more elongate antero-posteriorly 

 in the derived long-bodied types. The variations in the relative antero-posterior width 

 of the opercular flap are also correlated in part with body-length; very probably the prim- 

 itive carangid had a relatively short, deep opercular. It also appears highly probable that 

 in the primitive carangid the mouth was small, with rather long ascending processes of the 

 protrusile premaxillse, and that the quadrate-articular joint was moderately far forward, 

 perhaps beneath the middle of the orbit; that subsequently larger mouths were acquired 

 along with lo:.ger, swifter bodies and more predaceous habits, either by a moderate backward 

 shifting of the quadrate-articular joint, as in Coryphcena, or by a forward growth of both 

 snout and jaws, as in Trichiurus. 



Among the numerous skull characters of the Carangidae noted by Starks (1911a, p. 30) 



