OF THE BRITISH ISLANDS. 89 



the modification already recorded of the Sword-fish, only 

 in' these two instances it is the lower in place of the upper 

 jaw that is the more developed. A remarkable peculiarity of 

 the Gar-fish when boiled, is the fact that the bones assume 

 a bright green hue ; this circumstance has won for it the title 

 of the " Greenbone," and among the uninitiated has given 

 rise to the erroneous idea that the tint is due to the presence 

 of copper, and that the fish is therefore unfit for food. A 

 very interesting series of the metamorphoses of this species 



FIG. 20. — FLYING-FISH {Exocetus volitans). 



from the egg to the full-grown fish will be found in the 

 spirit series of the Day Collection. Young examples in 

 which only the lower jaw is abnormally developed, were 

 originally described as a distinct species under the title 

 of the " Half-beak " (Hemiramphus). The greater Flying- 

 fish {Exocetus volitans), No. 159, rarely captured in British 

 waters, in shape, size, and colour much resembles a Herring, 

 with the exception that the pectoral fins are so enormously 

 developed that the fish is enabled with their assistance to 



