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nearly their full number of rays. The pectorals, however, are so small that they 

 can be discovered only in particularly good light. 



When 12 — 13 mm long (plate II, fig. 11), the form of its body and fins is 

 already very like that of the grown-up flounder. — 



The plaice also is met with on the sands, 10 — 11"'"' of length (the largest 

 specimens at the pelagic stage are at least as long). It is very longish, much 

 more so than flounders of the same length; by the large number of rays in the me- 

 dian fins it is easily distinguished from the flounder. 



When 12 — 13 mm (plate II, fig. 10), it is still more longish (» sole-shaped ») 

 and the form of its body, as well as the number of its rays, makes it very like 

 common dabs of the same length. Yet it is easily distinguished from the latter 

 by its small eyes (the diameter of the apple of the eye is only half the length of 

 that in the average-sized common dab), and by a different pigmenting. 



I never met with quite young common dribs on shallow water or together with the 

 fry of plaice and flounder ; indeed, I have got them only from one place (at Mv0) 

 on 15 fths. of water (plate II, fig. 9); a single common dab, 1 — 2 inches of length, 

 I have met with however on shallow water, though very rarely, among thousands 

 of plaice. 



When the flounder has reached a length of c. 28 m "\ the spines, which are so 

 characteristic, appear at the base of the dorsal and anal fins. They are best seen 

 when we bend the fins downwards, and look at the spines from the side through 

 a magnifying lens. 



At first the spines appear singly, and issue from the hind edge of the scales 

 which are situated, one for each interspinous bone, along the base of the said fins. 

 Before these spines are visible, it will generally be necessary to count the number 

 of fin-rays, in order to distinguish flounders from plaice with certainty. The time 

 when the young fish appear on the shores, and the frequently sinistral specimens 

 among the flounders, moreover, afford holds for the determination. — The young 

 plaice appear on the shore, it seems, a little earlier in the year than the young 

 flounders, and are, particularly at a certain time, as a rule considerably larger. 

 (See the tables.) 



When the common dab has reached c. 20 mm of length (perhaps even before 

 that time), the lateral fine becomes distinct, considerably curved over the pectoral, 

 and it is impossible by closer examination to mistake the fish for any other 

 nearly related species. 



