of the Fishery Board for Scotland. 



269 



thrown into the sea, and had thus been left by the tide. The pools 

 at both east and west rocks were in some cases semi-solid with them. 

 Their enormous numbers must have exercised a considerable influence on 

 the food of the fishes in the Bay and near it ; and the stomachs of those 

 examined — e.g.," sprats, fifteen-spined stiklebacks, armed bull-heads, and 

 whiting — were distended with them. They consisted of Nyctiphanes and 

 Thysanoessa. 



A few Appendicularians made their appearance at the end of the month, 

 but they probably were in the Bay sooner, since young forms were 

 procured in February. They at any rate were not in the profusion so 

 characteristic of April 1887, when the huge mid-water net frequently 

 filled like a balloon with them and their 1 houses,' and this — day after 

 day, so that the patience of the boatman was nigh exhausted by the 

 heavy work thus entailed. It was a relief to him when they diminished. 

 There can be little doubt that, like other Ascidians,'they are eaten by fishes 

 of all kinds, and thus their great numbers make them important elements 

 in the food of that group. They have long been known to occur in 

 abundance in Scottish waters; for Edward Forbes, in 1845, found that the 

 cloudy patches of red colouring matter in the sea off the north of Scotland 

 consisted almost entirely of them. They were also frequently met with 

 in the work for the Trawling Commission under Lord Dalhousie. Their 

 prodigious numbers, however, were only clearly estimated at St Andrews. 

 The forms which occurred in the Bay were almost colourless, and thus 

 differed from Forbes's examples and many of those procured in the 

 expeditions just named. 



They fed freely, apparently on the peculiar gelatinous algoid structure 

 in 1887, and the vessels in which they were kept were littered with 

 small brownish, cylindrical fcecal masses, which apparently represented 

 algoid structure altered by digestion. During the months (April and May) 

 in 1887 in which they were under observation, their size considerably 

 increased. Their disappearance in May was as sudden as their advent in 

 such enormous numbers in April. As a rule, the Appendicularians have 

 their reproductive organs fully developed during this month. 



In April 1887 one of the most remarkable features of the pelagic fauna 

 for some weeks was the occurrence, almost daily for a week or two, of 

 Clione borealis, Pallas, a pteropod (mollusk) hitherto considered one of 

 the rarest of British marine animals. Indeed, Dr Gwyn Jeffreys, long the 

 authority on the group, and who had searched the British seas more 

 thoroughly than any other in recent times, could only observe in regard to 

 its occurrence, that Dr Leach, during a tour in the Orkneys (? Hebrides) 

 in 1811, says he found several mutilated specimens on the rocks, and 

 succeeded in capturing one alive on the coast of Mull. Like others of the 

 group, it forms part of the food of the whale, and it need hardly be said 

 is a prize for any food- fish. The species is one of the most beautiful as 

 well as the most graceful in motion amongst the pelagic animals of our 

 shores. None occurred in the Bay in 1888. 



Amongst the pelagic ova were those of plaice, cod, haddock, whiting, 

 dab, rockling, and flounder, those of the gurnard appearing at the end of the 

 month, though in former years occasionally at the beginning. Others not 

 yet clearly differentiated were also procured. The comparative scarcity of 

 ova in the upper waters of the Bay is in marked contrast with the rich 

 grounds in the Moray Firth, Smith Bank, and the region south-east of the 

 Isle of May. It may be truly said that the pelagic ova are an index of the 

 kind and number of the adult fishes in the neighbourhood. At the end of 

 the month pelagic ova of the ling are found at a distance from land, but 

 none have been recognised in the Bay. In glancing with a lens at collec- 



