of the Fishery Board for Scotland. 



225 



ovary, and reckoning only 1 5 lbs. as the weight of eggs which it contained, 

 we get 1,327,000 as the number of eggs in a fish of 91 lbs. weight. This, 

 of course, is only a rough calculation, but will give an idea of the immense 

 number of eggs produced by this species. 



9. Zeugopterus unimaculatus (Risso). — I took this species on several 

 occasions in Loch Fyne during last summer, mostly in a small sandy bay 

 on the west shore. It seems to be fairly common in that particular spot, 

 as on one occasion I took three specimens at one haul of the trawl. 

 Another specimen was taken near the east shore of Lochfyne in 10 

 fathoms of water. It lives well in confinement ; and we kept two speci- 

 mens alive all the summer and autumn, and they were only preserved 

 when the station was closed for the winter. It swims about with a grace- 

 ful undulating motion of the vertical fins, resembling the movements of a 

 sole rather than those of any of the species of Pleuronectes. The vertical 

 fins almost meet under the tail, and in the terminal portion the rays are 

 very flexible, and not covered with spinous scales as is the case with all 

 the other rays of the dorsal and anal. The first ray of the dorsal is pro- 

 duced into a somewhat long, fleshy filament, which is sometimes branched. 

 The distribution of colour in this species is very eff'ective, and the large 

 central spot, often edged with white, which is situated on the lateral line 

 some distance in front of the tail, is very well marked. The amount of 

 the darker shades present (which vary from brown to an intense black) 

 varies very much with the light and the nature of the bottom. Sometimes 

 the specimens were marbled all over with black and white in broad, 

 irregular patches. At other times the general ground colour was a lightish 

 brown marbled with yellowish patches and dark brown spots, and with a 

 number of brilliant red spots about the size of a pin's head. At such times 

 the central large spot already referred to is brought out in great relief, 

 but it can always be made out even when the general body colour is 

 almost black. 



The specimens which I have obtained difi'er in many minor points from 

 the figure given by Day [British Fishes, vol. ii. pi. 99 fig. 1). The lower 

 jaw is not curved, and the interorbital ridge is not prominent in living 

 specimens. These effects may, however, be produced in specimens pre- 

 served in strong spirit. The pectoral fin has not the thickened and pro- 

 longed spine shown in Day's figure. The anal fin gradually narrows 

 anteriorly and terminates between the two ventral fins but is not attached 

 to them. The angle of the vertical fins in the caudal region is usually 

 not so marked as in Day's figure ; the rays gradually decrease in size 

 near the margin of the caudal, where they are scarcely one-sixth of an 

 inch in length, and then become longer again under the caudal forming the 

 * accessory portion ' already spoken of. The markings on the upper sur- 

 face vary considerably, both in size and intensity, but the one spot on the 

 lateral line is prominent and constant. It is, I suppose, for this reason 

 that the species has received the name unimaeulatus. 



There are also a number of short fleshy filaments studded around the 

 baise of the vertical fins, and more sparingly over the general upper surface. 

 These are usually black, but in the lighter areas some are very pale. 



In confinement the specimens usually adhered to the sides of the tanks 

 in which they were placed, and were seldom found on the bottom, even 

 when this was covered with sand. This fact seems curious, as in their 

 natural habitat they were found in a small sandy bay overgrown with 

 Zostera marina. In a glass tank their habits could be easily watched. 

 The fish on approaching a side of the tank would press itself flat against 

 the glass, and then, with a slight backward pressure of the rays of the 

 dorsal and anal, the body is raised up a little from the surface of the glass, 



P 



