88 THE FRESH-WATER FISHES OF EUROPE. 



Fleuronectes italicus (GUNTHER). 



D. 6064, A. 4148, P. 1112/1011, V. 6, C. 12. 



This species, the Platessa passer of Bonaparte, is known in Italy, ac- 

 cording to Canestrini, as Pianuzza passera. It is common in the Adriatic Sea, 

 and goes up the Adige and other streams. Many Continental writers regard 

 it as identical with the Flounder. 



A bony keel divides the head into two parts. The space between the 

 eyes is naked and small. At the bases of the dorsal and anal fins are rows of 

 small accessory spines. The anal fin has one spine directed forward. The 

 small scales have a semicircular form. The teeth are strong, blunt, and ai- 

 ranged in a single row. 



The head is one-fourth the length of the fish. The height of the body is 

 to the total length as ten to twenty-seven or twenty-nine. 



The vertical fins have large, brown, irregular spots. 



The Plaice, Pleuronectes platessa (Linnaeus), has been found by Steindach- 

 ner in the rivers of the south of Spain, and is common in many estuaries of the 

 south of France and England. In East Friesland it has been placed in fresh- 

 water ponds, where it thrives well. 



Solea vulgaris (CUVIER). The Sole. 



D. 7386, P. 7, V. 56, A. 6173, C. 16. Lat. line 160. 



The Sole is essentially a marine fish, yet it is not only capable of -being 

 naturalised in fresh water, but in some rivers is said to have developed marked 

 characteristics. It is remarkably hardy, and commonly migratory. It 

 retires to deep water in winter, and comes into the shallow sea with the 

 warmer weather of April or May. It lives on a sandy bottom, above which 

 it does not rise far. 



It varies in size and colour with the fishing-ground, being small on the 

 east coast of England, and large on the south and south-west coast. The 

 largest Sole mentioned by Yarrell was twenty-six inches long, and weighed 

 nine pounds. 



McCulloch was the first to draw attention to the circumstance that Soles 

 have been kept in confinement in fresh-water ponds in Guernsey, where they 

 became twice as thick as fishes of the same length taken in the sea. And 

 Yarrell tells us that Soles frequent the River Arun, in Sussex, nearly up to 

 the town of Arundel, remaining in the river the whole year, breeding in it 



