364 FISHES OF THE FIRTH OF FORTH. 



This species of Flounder is distinguished by the upper 

 surface being perfectly smooth, except the middle of the 

 back along the course of the lateral line, and the base of 

 the dorsal and anal fins, which are rough with small round- 

 ed stellated tubercles ; by passing the hand down the back 

 they are readily felt. 



The Mud-Flounder, as it is frequently named in Scot- 

 land, is rather more common on our coasts than the last- 

 described species, and is found at the mouths of rivers 

 nearly all the year round, up which it sometimes ascends to 

 a considerable distance, particularly when the waters are 

 discoloured and increased in size by heavy rains. In ge- 

 neral, it is a dirty feeder, subsisting on slugs, worms, and 

 dead animal matter, and inhabiting muddy situations in 

 preference to fine sandy banks. In the months of July 

 and August these fish are taken in great numbers in the 

 Firth of Forth in the salmon nets, particularly above 

 Queensferry ; as well as in Leith Harbour with the hook. 

 They take the bait most eagerly, and require but little skill 

 in their capture. The average size is from seven to nine 

 inches in length, and one of double that is considered un- 

 common. The largest specimen I have met with taken from 

 the Firth of Forth, measures the length of sixteen inches. 

 Pennant has heard of them weighing six pounds. Those 

 found in the river are said to be held in higher estimation 

 for the table than those met with in the sea, and are at all 

 times inferior in flavour to the other species of flat fish. 

 They spawn in brackish water in March and April, and 

 the young are seen in June scarcely half an inch long. A 

 variety of this fish is often met with, with the eyes on the 

 left side of the head ; some authors formerly considered it 

 as a distinct species, under the name of Pleuronectes passer, 

 but since it differs in no other respect from the common 

 kind, naturalists are now agreed to make no distinction be- 

 tween them. 



