in the Fish Gallery of the Indian Aluseum. 7 1 



varieties of a species of carp. In a state of nature all 

 such varieties and monstrosities are — the conditions of 

 life remaining unchanged — kept down by an inexorable 

 competition ; but when Man interposes, he can, within 

 reasonable limits, preserve any variety or monstrosity 

 that takes his fancy. Of course there are some animals 

 that are not only more variable and plastic but also 

 more amenable to domestication than others, and the 

 Gold-fish appears to be one of these. 



Family IV. C ypvinodontidce [Case 67]. 



The interest of this family of fresh-water fishes — of 

 which 5 species are found in India — has been noticed in 

 the section on Geographical Distribution. 



Family V. Scombresocidce [Cases 70-71]. 



This family includes the Gar-pikes and Flying-fishes. 

 The Gar-pikes are marine, but have a tendency to pass 

 into estuaries and backwaters and so to furnish a com- 

 plement to the freshwater fauna. The Flying-fishes 

 are truly oceanic and are found in all the oceans in the 

 tropical and temperate zones. The Indian Gar-pikes, 

 Belune and Hemiramphus, also occur in all tropical and 

 temperate seas, including the Mediterranean. 



Family VI. Sternoptychidce [Case 70]. 



These are oceanic fishes which live at a considerable 

 depth below the surface. Their eyes are well developed 

 and their phosphorescent glands are abundant. The 

 genera that occur in Indian seas are Argyropclecus, 

 Sternoptyx, Polyipnus, Cyclothone, Photichthys, and Chan- 

 liodus. Of these, all but Polyipnus and Photichthys are 

 also found in the Atlantic; while Argyropelecus and 

 Chauliodus are also Mediterranean genera. In Polyipnus 



