178 GIANT FISHES 



having both their eyes on the same side of the head — the right 

 side or the left side. In the minds of many, the members of 

 this order (Halibut, Plaice, Dab, Turbot, Sole and so on) are 

 lumped together with the Skates and Rays as " Flat Fishes ", 

 but the resemblance between these two types is purely super- 

 ficial. Both have become adapted for a life spent mainly 

 upon the sea floor, and both have acquired a flattened shape, 

 but, whereas the body of a Ray is depressed (i. e. flattened from 

 above downwards), that of the true Flatfish is compressed (i. e. 

 flattened from side to side). Thus, the " upper " or coloured 

 side of the Flatfish, as it lies on the bottom, is really its right 

 or left side, and not the true dorsal or upper side as in the Ray. 

 The two sides of the Flatfish are usually referred to as the 

 " eyed side " and the " blind side " respectively. 



One point of special interest may be mentioned here. As a 

 general rule, a particular species of Flatfish is either right- 

 sided or left-sided, and not, as might perhaps be supposed, 

 sometimes right- and sometimes left-sided. Thus, to mention 

 the better-known British species, the Halibut, Plaice, Dab, 

 Flounder, Lemon Sole, Witch and Sole are all right-sided 

 species ; the Turbot, Brill, Megrim and Topknot are left- 

 sided species. In the case of the Flounder, however, as well 

 as in certain other species, reversed examples are fairly common, 

 but such individuals are abnormal, and the structure of the 

 fish leaves no doubt as to the side on which the eyes should be. 



This is a very large Order of fishes, and includes some of the 

 most important and valuable food-fishes in various parts of 

 the world. Only one type of Flatfish grows to a size sufficient 

 to warrant its description as a giant, namely, the Halibut, 

 and this may now be considered in some detail. 



HALIBUTS. 



(Family Pleuronectid^e ; Genus Hippoglossus.) PI. V c. 



Flatfishes with a rather long body, which is somewhat 

 rounded on the eyed side and flat on the blind side, and is 

 covered with small, more or less smooth scales. The eyes are 

 on the right side of the head, and are separated from one 

 another by a fairly wide, flat space. 



