THE TELEOSTEL 



135 



Amia. The bomologue of the siispensorium of the JEJiasmo- 

 hranchii is articulated with a surface furnished to it by the 

 postfrontal, pterotic, and proOtic bones. Usually it moves 



Ar AnSyPrO/x -Sro- 



10 /I 



Fig. 47.— Side-view of the skull of a Pike (^Esox licciu/i) : Prf. prefrontal ; IL 3/., hyoman- 

 dibular bono; Oj>, operculum; /S.Op., suboperculum ; I.Op, interoperculum; Pr, Op, 

 preoperculum ; Brr/, brunchiostcgal rays; Si/, syrai)lectic ; 3It, metii pterygoid ; P/, 

 palato-pterygoid arch ; Qu, quadrate bone ; J.>\ articular ; An, angular ; 2>, dentery ; 

 S.0/\ suborbital bone. 



freely upon that surface, but, in the PlectognatJii^ it may be 

 fixed. It ossifies so as to p:ive rise to two bones : an upper 

 broad hyomancllbular (IL3I.)j with which the operculum artic- 



FiG. 48.— Prdato-quadrate arch, with the hyomandibular and symplectic of the Pike, viewea 

 from the inner side; the articular piece {Art\ of the lower jaw, and Meckers cartilage 

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

 hyomandibular (iT". J/.), and the symplectic {Si/.); b, that which serves as a pedicle to 

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

 articulates ; d, head of the hyomandibular which articulates with the skull. 



ulates; and a lower styliform symjilectic (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 {I^l.) in front, and 



