18 



GURNARDS. 



organ appears to be in some measure subject to the will of 

 the fish, and also to be capable of sustaming the various 

 degrees of pressure which it must encounter when these fishes 

 rise, as they sometimes do, from a considerable depth in the 

 water to the surface. 



The fish of this family are placed by Linnaeus in the Thoracic 

 order. 



AIR-BLADDERS OF TRIGLIDvE. 



Red Gurnard. 



Grey Gurnard. 



Tubfisli. 



