ICHTHYOLOGICAL CONTRIBUTIONS. 327 



This specimen was probably only six or seven months old, having 

 been Latched in the preceding spring. 



Zctigojjterus unimaculatus, Risso, must be extremely rare on this 

 coast. I have never yet met with a specimen. The collection made 

 by Mr. Murray in 1887 and 1889 included only one specimen, taken 

 in the Firth of Clyde off Ardrossan. 



2. On a Stage in the Metamorphosis of Solea.* 



Plate XIV, fig. 2. 



The larva represented in fig. 2 was obtained by Mr. F. W. 

 Gamble on August 9th, when working with a hand-net among the 

 fronds of Laminaria on the inner side of Plymouth Breakwater. It 

 evidently belongs to the genus Solea from the shape of the snout, 

 mouth, and head generally. The larva was 11 mm. long. The 

 dorsal fin-rays are eighty-six in number, the post-anal sixty-eight, 

 so that it is certainly either Solea vulgaris or lascaris. I have not 

 been able to discover any indication of the enlarged nostril on the 

 lower side which distinguishes lascaris, and am therefore inclined to 

 believe that the specimen belongs to the common sole. The chief 

 difficulty in thus regarding it is the date of its occurrence. I have 

 taken completely metamorphosed young soles in Mevagissey Har- 

 bour on May 15th, but they have not been seen there later. How- 

 ever, I know that a few soles are spawning in May, although a 

 great many are then spent. But the larva here in question could 

 not be much more than a month or five weeks old, and must, there- 

 fore, have been spawned late in June or early in July. It is 

 possible that some soles spawn as late as this, although I have not 

 observed any ripe specimens in these months. The specimen when 

 alive was very transparent, as shown in the figure. The drawing 

 was made with the camera lucida, so that its proportions are 

 accurately correct to scale ; but the exact number of the fin-rays 

 has not been reproduced in the figure. 



There are several points of interest and importance in this larva. 

 It shows in the first place that in Solea, as in the genus Pleuronectes 

 — the plaice and flounder, for example — the eye of the lower side 

 passes round the edge of the head to reach the upper side, and not 



* While these pages were in the press I noticed, on referring to RafEaele's paper (Mitt. 

 Zool. Stat. Neapel, Bd. viii, tav. iii, figs. 8, 9), that a similar stage of Solea is there 

 described and figured. Thus the fact that the left eye reaches the right side in Solea by 

 passing in front of the dorsal fin was already known, but as Raffaele's description and 

 figures scarcely do full justice to this intermediate stage, the description and figure I have 

 given are by no means superfluous. 



