Holt — On the Eggs and Larvce of Teleosteans. 459 



It is difficult to refer this specimen definitely to any species. The measurements 

 of the ova of Solea vulgaris given by various authors are somewhat conflicting. 

 M'Intosh and Prince (o/:*. cit.^ p. 848) give '045 in. (roughly about l"125mm.). 

 A number which I pressed from a female and artificially fertilized measured 

 between 1'31 mm. and l"40mm. ; and others taken in the tow-nets at St. Andrews 

 in June, 1890, varied between l'25mm. and l'28mm. Cunningham's measurements 

 (Reproduction and Development of Teleostean Fishes, p. 18) are 1'41 to 1*51 mm.* 



Thus there seems to be in the single species a very great variation, pei'haps to 

 some extent governed by local conditions, as Cunningham's specimens, from 

 Plymouth, are much larger than any that have come under oar notice here. 



Of Raffaele's soles, the ova of his undetermined species, 1. Solea (?) (ojo. cit., 

 p. 63), approaches ours most closely in dimensions, being 1-4 mm. Solea, sp. A 

 and B, are respectively l*06mm. and 1"23 mm. in diameter (pp. 43-45). 



In the character of the vesicular layer of the yolk my egg differs from Solea 

 vulgaris, as described and figured by M'Intosh and Prince, and as observed by 

 myself at this place, in that the segments appear to be smaller and more numerous ; 

 but Cunningham [op. cit.) has shown that in this matter Solea vulgaris is subject to 

 individual variation. In my form the segments persisted some time after hatching 

 as conspicuous objects, a condition different to that indicated by M'Intosh and 

 Prince. 



As regards the oil-globules, the presence of groups of minute globules along 

 the sides of and under the embryo is a marked character of S. vulgaris, and of 

 Raffaele's sp. A and B, whilst it is wanting in his sp. 1. 



The presence of larger globules over the general yolk surface is peculiar, as 

 though M'Intosh and Prince's figure {op. cit., PI. ii., fig. 11), shows that in 

 S. vulgaris larger globules are present in the later stages of development (doubtless 

 by coalescence of smaller), yet in that form they are grouped with the smaller 

 ones, mostly about the ventral sm-face of the embryo, a condition which is not 

 found in our form even after extrusion. The colour and arrangement of the 

 pigment is very different from that of S. vulgaris. '\ 



The egg of Solea variegata,X described by Cunningham, approaches this form 

 very closely in dimensions, being only '02 mm. smaller, but differs in the 

 character of the oil-globules. 



* In his " Treatise on the Common Sole," Plymoutli, 1890, p. 84, this observer gives the dimensions 

 as 1'47 to 1*51 mm. 



t M'Intosh and Prince {op. cit.) describe and figure the pigment of the larval S. vulgaris as a stone- 

 grey, a condition in accordance with my own observations. Cunningham (" Treatise on the Common Sole," 

 pi. XVI., figs. 3 and 4) figures the pigment as a brilliant orange, and does not allude to the work of previous 

 observers. 



% In his recent work, Cunningham gives the dimensions of this egg as 1-28 to 1-36 mm., and figures 

 both eggs and larvse. 



TEANS. ROT. DUB. SOC, N.S. VOL. IV., PiKT VII. 3 T 



