90 EGG AND LARVA OF CALLIONYMUS LYEA. 



the part of the yolk beneath the blastoderm, and accompanies the 

 latter in its gradual extension, just as in the eggs of Solea and in 

 other cases where the peripheral yolk-segments occur. 



There can, I think, be no doubt about the identification of the 

 eggs I refer to. I have never found in the egg of any other species 

 anything resembling the hexagonal reticulation in the membrane of 

 the egg of the dragonet. The size of the eggs described here was 

 '81 and '83 mm. in diameter, while those described in my former 

 paper measured '90 and "97, a variation not greater than that which 

 occurs among the eggs of a given species. 



Mr. Holt (loc. cit.) has given figures of the larval dragonet when 

 just hatched, and about twelve hours after hatching. I am able 

 now to give a figure of a later stage. The larva depicted in fig. 3 

 was drawn on May 14th, and hatched from an egg taken on May 6th, 

 so that it was probably five or six days old. The yolk is entirely 

 absorbed, but the larva retains some of the characteristics mentioned 

 by Holt. There are marginal pigment spots on the embryonic fin- 

 fold, but they are more numerous than in the stage figured by Holt ; 

 while there is no band across the tail, but pigment over nearly the 

 whole of the post-anal portion of the body. The pectoral fin is large. 

 The snout has still a somewhat pointed form, but the region of the 

 mid-brain is much more prominent than in Holt's stage. Holt speaks 

 of only one pigment, a bright orange, dark by transmitted light, and 

 I gather from his description that in the stages he examined he saw 

 no black chromatophores. I think this must be a mistake ; in any 

 case there are, as usual, both black and coloured chromatophores in 

 the stage I am describing, the coloured cells being light yellow by 

 reflected light and darker yellow by transmitted. The length of 

 the larva was 4*7 mm. 



DESCRIPTION OF PLATE V, 



Illustrating Mr. Cunningham's paper on " The Egg and Larva of 



Callionymus lyra." 



Fig. 1. — Egg of Callionymus lyra, taken May 14th, 1891. Zeiss A, Oc. 3. Under cover- 

 glass, drawn with Abbe's camera lucida. 

 hi. Blastoderm. 

 y. s. Yolk-segments. 

 Fig. 2. — Another egg at a later stage of development. Drawn with the same combina- 

 tion, without cover-glass. 



k. V. Kupffer's vesicle. 

 i/,s. Yolk-segments. 

 Fig. 3. — Larva of same species some days after hatching. Drawn May 14th, 1891. 

 iss aj, Oc. 3) camelra. 



