THE FLOUNDER FAMILY. 347 



the general colour of the body yellowish or buff, though the 

 middle of the tail-region is profusely speckled with black, and 

 similar pigment occurs on the head, jaws and other parts. The 

 fish at this stage is as symmetrical as a round fish, only a very 

 slight elevation of the right eye having taken place, and it is a 

 free-swimming form for a considerable period. 



In the next stage the body increases in depth, though little 

 if any in length, and the space between the vent and the snout 

 is longer. The true tail is developing below the larval tail 

 which projects prominently above it, and which has temporary 

 (embryonic) rays (Plate XIV, fig. 3). Thereafter the body 

 becomes somewhat triangular in outline, so that while the 

 length is only 6 mm. the greatest vertical diameter is 3 mm. 

 The head of the fish is still disproportionately large — larger than 

 is usual in such forms. The dorsal line is nearly straight from 

 a point above the otocysts (ears) to the base of the tail, but the 

 ventral line slopes rapidly downward from the tail to the 

 vent, and again rises, with an anterior convexity, to the jaw. 

 Holt finds a little over 70 rays in the dorsal, and about 65 in 

 the anal fin, in a similar example from Ireland. Papillae 

 indicate the developing ventral fins. Both surfaces of the 

 body are minutely speckled with black points, but the right is 

 more uniformly marked in this way. The specks extend to the 

 marginal fins, but not over them. 



The changes which follow, as seen in the next older forms 

 (Plate XIV, fig. 6), are the slight increase in the depth and 

 plumpness of the body posteriorly, the elongation of the rays of 

 the marginal fin, and the appearance of five or six touches, caused 

 by aggregations of dots, in the dorsal, the ventral still remaining 

 speckled as before. The closely approximated ventral fins have 

 likewise minute black points, but the breast-fins remain pale. 

 The right eye meanwhile is gradually passing upward, and the 

 embryonic fin is rapidly disappearing. 



The next phase (Plate XIV, fig. 7) consists in the ex- 

 tension of the abdominal wall ventrally, the increase in the 

 distribution of the pigment, — the left side still remaining 

 slightly speckled, while the right is densely coloured, — the more 

 evident grouping of the pigment in " touches " in the fins both 



