SYSTEMATIC CATALOGUE OF FISHES. 38 



Suborder HETEROSOMATA. The Flat-fishes. 



These fishes are remarkable for their bodily asymmetry, one side being 

 much more highly developed than the other. They hve almost exclusively on 

 the bottom, and one side, which is applied to the bottom, usually lacks color, is 

 flatter than the other, and has no eye. In their early stages, these fishes are 

 bilaterally symmetrical and swim as other fishes do; but as they grow they swim 

 more and more obliquely, and the eye on one side begins to move to the other 

 side of the head, and before they have attained the length of an inch or two, they 

 have permanently assumed a one-sided position, with both eyes on one side of 

 the head. Two families, the flounders and the soles, may be recognized, distin- 

 guished by the following characters: 



i. Mouth comparatively large, with teeth; eyes large, weU separated; margin of preopercle 



more or less distinct, not concealed by skin Pleuhonectid^ (flounders). 



ii. Mouth very small, twisted, without teeth or with only rudimentary teeth; eyes very small, 

 close together; margin of preopercle concealed by skin Soleid^b (soles). 



Family PLEURONECTID^. The Flounders. 



A numerous family of important fishes, mostly marine, found chiefly on 

 sandy bottom, and feeding on fish, Crustacea, and other animals. Some species 

 inhabit very deep water, some very shoal water, and others intermediate depths. 

 All are edible and some of them rank among the most valuable of marine fishes in 

 America, Europe, and Asia, chief among them being the halibut (Hippoglossus 

 hippoglossus) of the North Atlantic and North Pacific oceans. The body is much 

 compressed, deep, and elliptical in shape; the head is twisted so as to accommo- 

 date both eyes on one side; the premaxillary bones are protractile; the gill-arches 

 are 4 in number, and pseudobranchise are present; there is no swim-bladder; the 

 viscera are in the anterior part of the body, and the vent is close to the head; the 

 scales are of various form, and usually small; the lateral line, rarely absent, 

 extends on the caudal fin; the dorsal fin, composed only of soft rays, begins on 

 the head and extends nearly to the caudal fin; the anal fin is similar but shorter; 

 the caudal fin is sometimes continuous with dorsal and anal; the pectorals, rarely 

 absent, are placed rather high on the side, and beneath them are the ventrals, 

 one of which is sometimes lacking. The species are oviparous, the eggs being 

 small and numerous. Of the 40 or more genera represented in American waters, 

 7 are known from the North Carolina coast or on the adjacent ocean bottom. 



The flounders are of considerable economic importance in the state, and 

 their value appears to be increasing. In 1889 only 48,200 pounds, worth $872, 

 were sold by the fishermen; in 1897 the catch had risen to 173,975 pounds, 

 valued at $3,199; while in 1902 (the last year for which statistics are available) 

 there were taken for market 261,760 pounds, which brought the fishermen 

 $5,256. Nearly the entire product comes from Beaufort, Carteret, Dare, Hyde, 

 and Pamlico counties, and it is composed largely of several species of Paralich- 

 thys. 



