THE FLOUNDER FAMILY. 361 



Further development consists in a reduction of comparative 

 length, so that in the stage 12 mm. long the length of the body 

 is only 3^ that of the head, and only 2| times the greatest 

 breadth (height). The dorsal and ventral patches of pigment 

 are still more pronounced, and the pigment of the tail forms a 

 single transverse bar. The number of dorsal fin-rays has in- 

 creased to 72 and the anal rays to 54. 



At a length of 12'87 mm., or a little under |- inch (Plate 

 XV, fig. 3), there are several marked differences from the 

 preceding. The body has still further increased in proportionate 

 breadth, the length being about 2^ times the length. The 

 eye is well on the right side and the dorsal fin has advanced 

 forward to just below its hind border. The black pigment is 

 more plentiful and has invaded the dorsal and anal fins. The 

 lateral line can now be traced, and little groups of brownish 

 pigment-spots are grouped over the ocular side, on the future 

 upper surface. These give the little fish a brownish-grey colour. 

 The specimen figured had 68 dorsal fin-rays and 55 anal. 



In Plate XV, fig. 4, is seen the young plaice of 21 mm. 

 length (or about | inch). Although in some respects differing 

 from the adult, yet it could not at this stage be mistaken for 

 any other species. The breadth (height) is now about half the 

 length and both eyes rest on the right side. The forward 

 migration of the dorsal fin is almost complete. The groups of 

 brown spots have now been broken up and the whole right side 

 is covered with diffusely distributed brown pigment. 



The young fish is completely equipped for a life on the 

 bottom, with brown coloration in harmony with its sandy 

 surroundings (Plate XV, fig. 5). As already stated, the pelagic 

 habitat is forsaken at a stage of about \ inch in length, so that 

 the brown pigment and most of the black appear after the 

 change, to a ' bottom ' life. 



As regards the distinction between the young plaice at 

 these ' bottom ' stages, and the young dabs and flounders at the 

 same stage, we must refer the reader to the parts under the 

 headings ' Dab ' and ' Flounder.' We may here mention that 

 the number of fin rays in the young plaice from 11 to 53 mm. 

 in length varied from 80 to 61 in the dorsal fin and 57 to 46 



