OSSEOUS FISHES. 



549 



The Flounders and Plaice (Platessa) inhabit the northern seas of 

 Europe. They have their eyes placed on the right side ; ilhe dorsal 

 as well as the anal fin extending from over the eyes to the caudal 

 both stretching out to a point towards the centre, giving a rhombic 

 form to the fish. In Platessa the jaws are furnished with a single 

 row of obtuse teeth. 



The Common Plaice, P. vulgaris (Pig. 372), attains the length of 

 ten or twelve inches ; it is brown above, spotted with red or orange. 

 On the eye-side of the head are some osseous tubercles. The body, 

 which is somewhat lozenge-shaped, is smooth. 



Fig. 372. The Common Plaice (Platessa vulgaris). 



The Flounders (P. flesus) are fresh-water fishes of small size, 

 abundant in the Thames and many other rivers ; they are only second 

 in importance to the soles and turbot among the Pleuronectidae ; the 

 numbers of brill, flounders, dab, and plaice required being close upon 

 a hundred million for the supply of London alone. 



The usual mode of capturing flat-fish is by means of a trawl-net, 

 but many varieties of these may be caught with a hand-line. "A day's 

 sea-fishing," says Dr. Bertram, in his " Harvest of the Sea," " will 

 be chequered by many little adventures. There are various minor 

 monsters of the deep that will vary the monotony of the day by occa- 

 sionally devouring the bait. A tadpole fish, better known as the sea- 

 devil, or angler, may be hooked ; or a visit from a hammer-headed shark, 



