THE FLOUNDER FAMILY. 379 



flounder with 8 mm., the pelagic state of the common dab, 

 though it belongs to a smaller species, does not seem to be 

 at an end till the fish has reached a length of 12 to 13 mm." 

 He also found that the fin-rays of young dabs of 14 to 46 mm. 

 varied from 73 to 65 in the dorsal fin, and 55 to 51 in the anal 

 fin. From this and the observations of other workers, it is 

 evident that the number of fin-rays is a doubtfully distinctive 

 feature between plaice and dabs, at any stage, though, as will 

 be seen later, it forms a ready method of separating these two 

 species from the flounder on the one hand and from the witch 

 and lemon -dab on the other. 



We may note in Plate XVI, fig. 7, the appearance of the 

 lateral line with the anterior curve characteristic of the adult. 

 A detailed description of the pigmentation is unnecessary with 

 the figure before us. 



*j 



Later, the young plaice develop the adult tubercles upon 

 the ridge between the eyes, and later still the dorsal and anal 

 row of tubercles at the base of the fin-rays distinguish the 

 flounder, and the curved lateral line indicates the dab. The 

 number of fin-rays appears to increase with the age of the 

 young fish up to the number found in the adult. 



Little dabs of about 1 inch in length are found on St 

 Andrews sands and in the Forth in January and February, and 

 these, even when the lateral line is not visible, differ from 

 young flounders in their more elongated outline and larger 

 eyes, features at once recognised by a cursory inspection. 



The post-larval forms have yet to be exhaustively dis- 

 tinguished from those of the flounder, and perhaps other 

 pleuronectids, but the figures given probably indicate then- 

 general characters. 



As regards the rate of growth of the dab there is a good 

 deal of uncertainty concerning the young stages. The dab 

 appears, according to the work of Mr Williamson, to have a 

 curve of growth closely similar to that of the lemon-dab, though 

 the former seems to grow more rapidly during the first year. 



Young dabs are found in the estuary of the Thames in 

 October and are caught in the shrimp-trawls. They vary from 

 1^ inch to 3 inches in length. The smallest of these must 



