SPINY-FINNED FISHES. 



327 



appearance of a Mackerel, with a cartilaginous 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 (Ddphinus), to be described hereafter. Nevertheless, 

 the Coryphaenae 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. Tin's alternation of tints 

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

 down to a dull leaden hue. 



F;o 256 



' 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/' 



