354 THE FLOUNDER FAMILY. 



five or six V-shaped chroraatophores are found near the margin 

 of the dorsal fin behind the yolk-sac, almost intermediate be- 

 tween it and the tip of the tail, and two similar, or sometimes 

 triangular ones are present ventrally opposite the former. The 

 large oil-globule (slightly elliptical in certain views) lies at the 

 posterior and inferior part of the yolk, and has the usual black 

 chromatophores. The ears form simple sacs, and the eyes are 

 colourless. The rudimentary backbone (notochord) is distinctly 

 multicolumnar. The solid strand of the gut posteriorly comes 

 to the edge of the marginal fin, and a pre-anal portion occurs 

 between it and the yolk. 



On the third day of larval life, yellow pigment is apparent 

 amongst the black in the marginal fin, and along the sides of the 

 body posteriorly. None is present on the head. The yolk-sac 

 as a rule has no pigment, though occasionally one or two black 

 corpuscles appear at the upper region. It has to be noted, 

 however, in the case of those retained longer in the egg, 

 that yellow pigment occurs on the tail. The mouth is widely 

 open on the 6th day, and the yellow pigment is largely 

 increased along the muscle-plates, pre-anal region and other 

 parts. Black pigment is developed in the eyes on the seventh 

 day, and the yolk has greatly diminished. Though the cartilages 

 of the jaws are much less developed than in the gadoids, yet 

 the aperture of the mouth is proportionally large and the 

 movements extensive (Plate XIV, fig. 11). 



The larva of this species is thus distinctly characterised, and 

 can be readily separated from that of the gurnard or other forms 

 with which it has occasionally been confounded. The eggs are 

 comparatively large and not very numerous, while the adult is 

 seldom procured in numbers. 



Holt found a series of small specimens off the Skelligs on 

 the west coast of Ireland, on the 19th August, ranging from 19 

 (Plate XIV, fig. 12) to 56 mm.' The right eye has passed the 

 ridge at 19 mm., is a little in advance of the left, but is 

 upwardly directed ; the lateral line is visible, but its anterior 

 portion has only a simple curve. Indications of the pigment- 



' Specimens from 30 to 40 mm. in length also occurred in July in the same 

 area. 



