CLASS OF FISHES. 



339 



bones is found at the bottom of the mouth supporting the 

 gills, and seemingly analogous to the hyoid apparatus 

 (Fig. 309), extremely developed. 



The bone of the tongue (I) is continued backward with a 

 series of pieces, and articulates on each side with a very long 

 and very large lateral branch (b), and this by its opposite 

 extremity is suspended to the lateral partition of the head, 

 already described. These lateral branches, formed of several 



ph ar 



co ca ab h 



Fig. 309. Head and Respiratory Apparatus of a Fish.* 



bones, support inferiorly a series of flattened curved rays (r), 

 which assist with the opercular to complete the walls of the 



* Fig. 309. Osseous head of the Perch, partially dissected, so as to show 

 the interior of the mouth and the hyoid apparatus : c, cranium ; or, orbit ; 

 v, vomer, armed with teeth ; im, upper jaw ; dp, teeth fixed into the pala- 

 tine arch ; m, lower maxillary ; I, lingual bone ; b, lateral branches ot the 

 hyoid apparatus ; s, stylet serving to suspend these branches to the inner 

 surface of the jugal partitions ; r, radii branchiostegi : a, branchial arches ; 

 ph, superior pharyngeal bones ; ar, articular surface of the partition already 

 mentioned ; o to h, osseous girdle supporting the pectoral fin ( p) ; o and o', 

 scapula, formed of two pieces ; h, humerus ; ab, bones of the fore arm ; 

 ca, carpal bones ; co, coracoid bone. 



z2 



