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Part III. — Seventh Annual Report 



the pelagic forms, since they are reptant. The plutei of the sand- and 

 brittle-stars, as well as those of the Echinoids and Spatangoids, had not 

 yet appeared in the superincumbent water. 



The pelagic annelids captured in the mid-water net were the sexual 

 form of Nereilejoas, the ovigerous Autolyhis prolifer, and Tomopteris 

 about | inch long. Some of these occurred in the surface-net. Towards 

 the end of the month larval Terebellids and Spionidre were procured in the 

 bottom-net. 



In the surface-net Sagittae appeared occasionally, but they were small 

 (J to J inch). In the mid-water net they were more abundant, and the 

 range in size greater, viz., from \ to 1 inch. 



The surface-net showed many Copepods, though as a rule they were less 

 numerous than in former years ; for instance, in 1884. They included 

 such forms as Calanus finmarchicus, Halitemora longieornis, and 

 Centropages hamatus. Halitemora Jinmarchicus, so abundant in the open 

 sea off St Abb's Head, was absent. 



Moreover, the Naiiplii of these and other crustaceans were numerous, 

 though less abundant than in 1884, when Evadne Nordmanni (one of the 

 Cladocera) also occurred at the surface. The greater abundance of Nauplii 

 in the surface-fauna of St Andrews Bay was one of the contrasts between 

 it and Aberdeen Bay in 1884. Towards the end of May many of the 

 Nauplii of the Cirripedes had settled as Cyx>ris-\wcvdd in the Eden and 

 other parts on shells and submarine bodies. 



Amongst sessile-eyed crustaceans captured in the mid-water net were the 

 ubiquitous Atyhis Sivammerdamii, which occurs in hundreds clinging to 

 sea-weeds off the west rocks; Atylus bispinosus, Gammar us marina (9 with 

 ova); Amphithoe littorina ( 9 with ova); Parathemisto oblivia, small female 

 bearing ova (28th May) ; Proto pedata, Idotea trieuspidaia (surface-net 

 occasionally) ; Eurydice pulchra, and Diastylis Eathkii (adult). Instead of 

 the foregoing, Ampelisais occurred in May in Aberdeen Bay. These sessile- 

 eyed forms are for the most part to be considered as accidental members of 

 the pelagic fauna, though they must take some share in the nourishment of 

 the larger forms of both young and old food-fishes. 



Many zoeae of C. ma?nas, Hyas, and other forms, and a minute Crangon 

 appeared in the mid-water nets, while towards the end of the month some 

 iu the Megalops-stage were also present. 



Swept down by the stream into the harbour and thence carried into the 

 mid- water net in the Bay, were several exuviae of larval insects, just as in 

 former years insects themselves occasionally made their appearance from 

 this stream, the Eden, and others. 



Moreover, in the harbour itself many of the young flounders caught in 

 the tow-nets at the mouth of the mill-lade, show young examples of 

 Anceus Edivardii parasitic at the margin of the muscle-plates, and the 

 tenacity with which they adhere, or fix themselves afresh when dislodged, 

 is remarkable. A deep pit is left on removal, and after boring into the 

 surface of the little flounder it thrusts out a tongue-like process apparently 

 for suction. 



The Appendicularians occurred generally throughout the month, both 

 in the surface- and in the mid-water nets. They especially affected the 

 lower parts of the water in great swarms. The larger forms indeed were 

 captured by the mid-water net, the smaller by the surface-net. The 

 longest were about -§ of an inch in length on the 10th May. It sometimes 

 happened that while Rhizosolenise occupied the surface and upper regions 

 of the water, the Appendicularians held the lower regions. 



The most conspicuous eggs in the Bay during May, in the mid-water net, 

 were those of the gurnard, which especially abounded towards the end of 



