254 



MAUKKTAI'.LE BRITISH MARINE FISHES 



This is the only specimen of the sole in the period of trans- 

 formation yet obtained in Britain ; it was taken on August pth, 

 and such stages must occur somewhere at an earlier date in the 

 year. They have not been seen at the surface like the young 

 turbot and brill, nor at the margin at low tide like the flounder, 

 nor have been captured near the bottom like plaice and dabs. 

 As they have an air-bladder it is probable that they swim near 

 the surface, or far from the bottom. 



The next stage of the sole which is known is that in which 

 the transformation is just complete, and the little fish is very 

 like the adult, but more transparent. This stage is represented 

 by specimens 12 to 15 mm. long (Vj inch to 4 inch) taken to the 

 number of fifteen at one time from the end of April to the middle 



Fir,. 1 18. Young Common Sole, just after its tranformation, alive and magnified. 



of May in the tide-pools of Megavissey Harbour, in Cornwall. 

 They had lost their air-bladder. Their ages may be reckoned at 

 about two months (Fig. 1 18). They were very much scarcer than 

 the flounders taken with them, and also somewhat older, that is to 

 say more advanced in development. It is evident that the soles do 

 not seek the marginal region at so early a stage as the flounder. 



Young soles between the end of their transformation and one 

 year of age have not yet been frequently observed in large num- 

 bers. At Plymouth and along the Cornish coast I searched for them 

 from time to time in the course of several seasons without success. 

 A few specimens less than 2 inches long were trawled by Mr. 

 Holt at the mouth of the Humber, in October and November, 

 and these in all probability were derived from the preceding 



