THE FLOUNDER FAMILY. 369 



of the marginal fin, which still shows very bright canary- 

 yellow touches of pigment. Dark pigment, however, has invaded 

 the outer half of each spot, and occasionally it is even more 

 generally developed. The five pigment-bars on the body are 

 still diagnostic on the eighth day, and a stellate black corpuscle 

 often appears at the base of each breast-fin, which shows a 

 somewhat symmetrical series of fine embryonic rays with dis- 

 tinct intervals. The jaws are motionless, but widely apart, and 

 the vent has also been open for some time. No blood-corpuscles 

 are visible in the heart, but in Cunningham's examples pale 

 corpuscles occurred on the fourth day. A marked incurvation of 

 the ventral margin behind the head is present. They lived till 

 the 11th day, and presented further a row of pigment-specks 

 (which became conspicuous after immersion in spirit) along 

 the ventral edge of the abdomen and clavicle. 



The lemon-dab has thus a very hardy larva, almost as 

 hardy as the plaice, and little difficulty would be encountered 

 in hatching and rearing it for a considerable time under 

 artificial circumstances. So hardy are the larvse that a number 

 lived about six days in a small glass cell 2 inches by ^ inch 

 deep, the water being filled up as it evaporated. 



The early post-larval condition of the lemon-dab is probably 

 that represented in 'Researches,' and in Plate XV, figs. 10 and 11, 

 showing re.spectively four and five isolated patches of pigment 

 along the dorsal and ventral margins of the muscle-plates. The 

 body is exceeded in depth by the embryonic marginal fin which 

 is yellowish, and the abdomen is prominent and slightly 

 pigmented. Both sides are similarly coloured. The tail 

 is abruptly narrowed, and the notochord proceeds straight 

 outward, even when the fish is 8 mm. in length. The lower 

 caudal rays and those immediately above are cartilaginous ; all 

 the others are membranous. The head and belly, at this time, 

 appear disproportionally large since the trunk is long and slender. 

 When the little fish reaches a little less than half-an-inch 

 (Plate XV, fig. 12 and fig. 14, page 59) the marginal fin is 

 appreciably narrower, while interspinous elements appear along 

 the edge of the trunk. The outline now slants from the tail 

 downward and forward so as to embrace the gut. Five pigment- 



M. F. 24 



