376 THE FLOUNDER FAMILY. 



it a reticulated aspect. The black pigment is later in its 

 appearance than the yellow, and consists of a few scattered 

 stellate spots. The lemon-yellow markings somewhat differ 

 from the chrome-yellow of the flounder, forming more distinct 

 lines in the dorso-lateral region. There are two pairs of 

 these longitudinal rows on the trunk, and a few days later 

 a line on the dorsal part of the marginal fin. This disposition 

 of the yellow pigment is seen, even more distinctly, in the 

 larva of 11 days (Plate XVI, fig. 4). By this date the eyes are 

 very clearly indicated by black pigment and by a greenish 

 metallic lustre. 



The larva, hatched on the twelfth day, is very small, being 

 only from j 1 ^ inch to 2'6 mm. in length (Cunningham and 

 Ehrenbaum), and is at once easily recognised by its distinctive 

 lemon-yellow colour arranged in bands as described above. Of 

 all pleuronectids, the larval flounder, when just hatched, most 

 resembles the dab, though one of us 1 has described an unknown 

 larva (Plate XVI, fig. 1), hatched in the laboratory which also 

 very much resembles the latter. 



The larval dab continues to develop its yellow pigment 

 in longitudinal bars, whereas the young flounder changes its 

 coloration considerably as described later. The crescent- 

 like arrangement of the chromatophores in the dabs reared in 

 1886 in the St Andrews laboratory are probably due to free 

 exposure to light. Dr Ehrenbaum, who carefully describes and 

 figures the early post-larval forms, has not noticed this in his 

 examples, and they have not been seen in free forms. The 

 young flounder of 13 days (Plate XVII, fig. 2) and the young 

 dab of 11 days (Plate XVI, fig. 4) can therefore at once 

 be distinguished, the differences being sufficiently striking 

 in a superficial comparison of the two forms. A young plaice 

 of the same age is also clearly differentiated by its large size 

 and the dorsal and ventral black rows with a sparse yellow 

 patch (see plaice). 



A dab in which the body has considerably increased in 

 depth while the eyes are still lateral is shown in Plate XVI, 

 fig. 5, in a fresh though somewhat altered condition. 

 1 W. C. M., llth Report S. F. B., p. 243, PI. X, f. 15. 



