^a^ 



I. THE ADULT SNAKE-FISH {Polyptevus). Photo by A. Rudland. 



2. ADULT GREY GURNARD. 3, 4. YOUNG OF THE SAME, 



The Shake-fish breathes by internal gills, and has the back fin made up of 

 many finlcts, and a short tail-fin. The breast-fins are used simply as balancers. 

 In the larval stage the fins have a very different form, breathing is performed 

 by external gills, and the breast-fins are used as supports. Note the very 

 different form of the back -fin and tail, and the enormous breast-fin of the 

 young Grey Gurnand. 

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