of the Fishery Board for Scotland. 



297 



In the mid-water net some mussels ranging from '045 to '07 inch were 

 obtained at the end of the month along with a few about 2 mm. in 

 long diameter, probably swept from passing objects. Moreover, a 

 Heteropocl (Atlanta) was added to the British Fauna. 



In the surface-nets mussels and other bivalves were nearly as numerous as 

 in the bottom-nets, the sizes of the mussels being the same, viz., from 

 •012 to - 015, these being the usual ranges of the pelagic forms found in the 

 Day at this season. The univalves were also plentiful and apparently of 

 the same types, such as Natica, Vehitina, and other forms in shallow 

 water. 



The study of the pelagic fish-fauna of the Bay in September presents a 

 contrast with that of the preceding months, for now the post-larval foou- 

 lishes have almost disappeared, if we except the gurnards and the 

 Clupeoids. The young round food-fishes had indeed greatly diminished 

 during the previous month, and therefore the disappearance was gradual. 



The mid- water net still captured small Pleurone^tids ranging from 5-5 

 mm. to 9 and 10 mm., probably dabs, while a young turbot of 11 mm. 

 was also obtained. The smaller examples of the former presented no 

 permanent rays in the fin. Young gurnards were not uucommon, varying 

 in size from 5 mm. to 12 5 mm., thus showing a considerable increase on 

 the previous month. Moreover, young Clupeoids made their appearance, 

 the specimens ranging from 7 to 13*5 mm., the latter size occurring only 

 after the middle of the month. Gobies were still frequent, their extremes 

 in length being 6 and 21 mm. Most w T ere small examples, viz., about 

 7 mm. Young examples of Gallionymus lyra (dragonet) occurred several 

 times s from 3 '5 to 10 mm. The former size appeared at the beginning of 

 the month, and presented the tapering larval tail with permanent rays 

 below. This is one of the forms in which pigment occurs on the ventral 

 surface of the abdomen in the post-larval stage, disappearing, as in the 

 goby, in the adult condition. Two young Cotti about 9 mm. long 

 complete the list in this net. 



Besides these post-larval forms, young whiting from 1 to 2J inches were 

 occasionally procured, and young pipe-fishes (Sygnathus acus) were 

 common. The latter ranged from 20 mm. to 2f inches. 



No fishes were captured in the surface-net, but in the bottom-net a 

 Clupeoid of 7*5 mm. appeared. 



October. 



The pelagic Diatoms and Algae were still in considerable numbers, along 

 with spores of Algae and Rhizosoleniae. All were most numerous in the 

 bottom- and surface- tow-nets. The number of species of Diatoms was 

 considerable. 



The surface-net throughout the month also presented a considerable 

 number of Infusoria — such as Geratium tripos, which occasionally appeared 

 in vast numbers, as on the 16th and 17th; G. furca, which was less 

 abundant ; G. divergens, very few of which occurred ; and the same with 

 Tintinnus denticulalus. 



The bottom-net again showed similar forms, and in the same pro- 

 portion, the most abundant species being Geratium tripos, while only 

 very few examples of O. divergens and Tintinnus denticulatus appeared. 



The Ccelenterata had now greatly diminished in the surface-net, only a 

 very few Pleurobrachiw of moderate size being present. A few ova 

 of the same form with the embryos, well advanced, were also obtained. 



The mid-water net captured many examples of Thaumantias hemi- 

 sphwrica from the beginning of the month to the 17th ; indeed tliey were 



u 



