THE TELEOSTEI. 



155 



take little or no share in the formation of the gape, which 

 is bounded above by the backwardly extended premaxillse. 



FiR. 47 



S.Or 



\.r AnSyPi:U/i Bra 



Fig. 47. —Side-view of the skull of a Pike (Eso.r lucius): — Prf, pre- 

 frontal; H.M., hyomandibular bone ; Op, operculum ; .S. O/)., sub- 

 operculura ; I. Op, interoperculum ; Pr.Op, preopeiculum ; Srg, 

 branchiostegal rays ; Sy, symplectic ; Mt, metapterygoid ; PI, 

 palato-pterygoid arch; Qu, quadrate bone; At; articular; An, 

 angular ; D, dentary ; S. Or, suborbital bone. 



Fig. 48. 



Fig. 48. — Palato-quadrate arch, with the iiyomandibular and sym- 

 plectic of the Pike, viewed from the inner side ; the articular piece 

 {Aii^. of the lower jaw, and Meckel's cartilage (J/c4.)of the Pike; 

 seen from the inner side :— a, the cartilage interposed between the 

 hyomandibular {H.M.), and the symplectic {Sy.) ; b, that which 

 serves as a pedicle lo the pterygo-palatine arch ; c, process of 

 the hyomandibular with which the operculum articulates ; d, head of 

 the hyomandibular which articulates with the skull. 



