SPIXY-FINNED FISHES. 



327 



appearance of a Mackerel, with a cartila,2:inous keel on the sides of 

 the tail. The common species is about a foot long. 



Fig. 255.— pilot-fish. 



The Dolphin Fish {Coryphxna) must not be confounded with the 

 true Dolphin (Delphinus), to be described hereafter. Nevertheless, 

 the Coryphrena) are equally subjects of universal admiration. 



During a calm these fishes, when swimming about a ship, appear 

 of a brilliant blue or purple, shining with metallic lustre in every 

 change of reflected light. On being captured and brought on deck, 

 the variety of these tints is very beautiful ; the bright purple and 

 golden yellow hues change to a brilliant silver, varying back again 

 into the original colours, purple and gold. This alternation of tints 

 continues for some time, diminishing in intensity, and at last settles 

 down to a dull leaden hue. 



F.G 2.i6. — CORYFH.EXA. 



'• Parting day 

 Dies like the Dolphin, whom each pang imbues 

 With a new colour, as it gasps away, 

 The last still loveliest, till, — 'tis gone — and all is grey. 



