THE TELEOSTEI. 



13G 



Amia, The honiologiie of the suspensorium of the Elasmo- 

 branchil is articulated with a surface furnished to it bj the 

 postfrontal, pterotic, and proOtio bones. Usually it moves 



ill- An SijPrO/\ -Bra 



f IQ. 47.— Side-Tiew of the skull of a Pike (Esox lualua) : Prf, prefrontal ; IT. 3f., hyoman- 

 dibular bone; Op, operculum; S.Op., suboperculum ; LOp, interoperculum; Pr, Op, 

 preoperoulum ; Brg, branchiostegal rays; Sy, symplectlo; Mt, metapterygoid ; pL 

 palato-pterygoid arch; ^«, quadrate bone; Ar, articular; An, angular; i>, dentarv: 

 S.Or, suborbital bone. . > = . . i < 



freely upon that surface, but, in the Plectognathi, it may be 

 fixed. It ossifies so as to give rise to tw^o bones : an upper 

 broad hyomandibular {H.M.), with which the operculum artic- 



Art 



Pig. 48.— Palato-quadrate areh, with the hyomandibular and symplectic of the Pike, viewed 

 from the inner side ; the articular piece i^Art), of the lower jaw, and Meckera cartilage 

 {Mck.) of the Pike ; seen from the inner side : «, the cartilage interposed between the 

 hyomandibular {S.M.\ and the symplectic i^S]/-) ; &, that which serves as a pedicle to 

 the pterygo-palatine arch ; c, process of the hyomandibular with which the operculum 

 ai-tieulates ; d, head of the hyomandibular which articulates with the skulL 



ulateS; and a lower styliform symplectic {Sy.), which fits into 

 a groove on the inner and posterior surafce of the quadrate, 

 and is firmly held there. 



The palato-quadrate arch is represented by several bones, 

 of which the most constant are the palatine {PL) in front, and 



