FISHES OF THE VICINITY OF NEW YORK 



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Fig. 1. BONY FRAMEWORK OF TAIL-FIN OF STRIPED BASS. SeeprgeB 



70 Hypural bones, supporting the tail; 71 bony fin rays of tail. 



Drawing by F. A Lucas 



The fins of fishes were originally hump-like projections from the 

 body, involving the V-shaped muscle segments and covered with a web- 

 like fold of skin bearing small bony scales. During the course of long 

 ages some of the bony scales on the fins became arranged in rows end 

 to end, and running from the margin of the fin toward its base. These 

 small rows of scales then fused together into jointed rods and so gave 

 rise to the bony fin-rays upon which the web is stretched. At first (that 

 is, in the most ancient fossil "ganoid" fishes and even in the modern 

 gar pike) the scale-like origin of all the fin rays is very evident, but in 

 the course of time the first few rays of- the back fin (Plate I) in many 

 fishes lost their jointed character and the outer ends became narrowed 

 down to a sharp point, this process culminating among the so-called 



