of the Fishery Board for Scotland. 



301 



Acartia longiremis, also a few NaupUi, exuviae of Bcdaniy and occasionally 

 a specimen of Atijlus sivammerdamii. 



The mid-water-net produced only the actively pelagic Parathemisto 

 oblivla, which, moreover, was sometimes in multitudes. They occurred 

 in every haul of the net in greater or less numbers. 



In the bottom-net Crustacea were much more plentiful, especially the 

 Copepods, which included Halitemora longicomis, Pseudocolanus elongatus, 

 and Calanus finmarchicus, all three being abundant, though the examples 

 of the latter were sometimes small. Parathemisto oblivia occurred oc- 

 casionally, but in limited numbers. 



The representatives of the Molluscoida were confined to the bottom-net, 

 and to one species, viz., Cyphonautes, but they still occurred in consider- 

 able numbers. The extended period during which this larval species fre- 

 quented the bottom-net is noteworthy. 



The Mollusca likewise were found only in the bottom-net, and consisted 

 of larval univalves of various kinds. It is remarkable that no pelagic 

 cuttle-fish was captured during the year. 



The post-larval fishes during the month appeared to be extremely rare ; 

 the only young form being a Clupeoid 1J inch long, which was obtained in 

 the mid-water-net. 



PELAGIC OVA AND LARVAL FORMS OF FOOD-FISHES 

 AND OTHERS. 



The pelagic ova are much more numerous in the surface-waters on various 

 fishing-banks, such as south-east of the Isle of May or North Carr, Smith 

 Bank, and on similar grounds, than in St Andrews Bay. The eggs, however, 

 captured in the tow-nets on these banks, present, as a rule, similar features. 

 They pertain, for instance, early in April to the cod, plaice, haddock, dab, 

 rockling, and others, besides the egg with the large peri vitelline space. They 

 are accompanied by larval forms of the same species. Certain observations 

 point to an earlier deposition by deep-sea plaice and other forms than by the 

 same species in shallow water. I£ this be sustained by further inquiries 

 the differences in size amongst the young of a season would so far be 

 explained. Hensen speaks of having found an ovum towards the end of 

 April with an oil-globule, and which he referred, to Crenilabrus. At St 

 Andrews the eggs of the gurnard occasionally appear, though sparingly, at 

 the end of April. They possess an oil-globule. Hensen obtained the ova 

 and larval forms of plaice in the Baltic towards the end of April. It 

 sometimes happens in spring that pelagic ova are much more plentiful near 

 the bottom than in the upper regions of the water, so that careful observa- 

 tions are necessary in any given locality before conclusions are drawn 

 with regard to their distribution. 



