218 THE COMMERCIAL SEA FISHES OF 



in the place indicated when they catch a flounder too small 

 to be saleable. As the notch heals the edges recede, so 

 the dorsal fin appears to commence further back than is 

 normally the case. Whether this is the explanation of all 

 such varieties may be questionable, as some are evidently 

 due to an arrest of development, as observed in the plaice, 

 turbot, &c. Thompson refers to the malformed head of 

 one resembling Yarrell's brill. 



Habits. It is found round our coasts, ascending rivers 

 to far above tidal influence, and is able to live in very 

 impure water. 



There is not much to say of its habits. Its name, 

 flounder, has been asserted to be derived from the Swedish 

 word Flundra, denoting its swimming close to the ground. 

 .Here it buries itself in the sand or soil, by working down 

 first one side of the body and then the other, and thus its 

 back becomes covered, while its elevated eyes and mouth 

 remain clear, for the purpose of seeing and capturing its 

 prey. In some rivers it is found among stones, or on the 

 side of sandy banks in mid-stream ; but muddy holes are 

 reputed not to be the places where it usually resorts. It 

 will wriggle itself up the sides of posts when under the 

 water, and it retains its hold by means of its vertical fins. 

 It is a greedy and voracious feeder, eating worms, slugs, 

 crabs, young fish, and animal substances. Thompson 

 found, in one he examined at Belfast, the remains of 

 Rissoa ulvcB ; and Johnston, off Berwickshire, obtained 

 from them Pecten obsoletus. 



That this fish ascends into fresh water is very certain. 

 If we turn to Belonius, De Aquitilibus, published in 1553, 

 we find it described as Passer fluviatilis, vulgo flesus. It is 

 said by Bloch and others that this name was given owing 

 to its colour being similar to that of a sparrow, and because 



