154 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
a few Echinoderm Plutei and Polychaet larvae, Ceratvum 
tripos, and some Diatoms, chiefly species of Rhizosolenia 
and Chaetoceras. But the bulk of the catch is, in all 
cases, Calanus helgolandicus, and that gives it a 
characteristic appearance which can be seen as soon as 
the net comes up. We have, in all, eight vertical hauls 
taken during July in the years 1907, 1908 and 1909 (some 
of these are given in detail in the tables below), and also 
a surface gathering taken at the same locality on July 28, 
1908. ‘This surface gathering is, however, of an entirely 
different character from the vertical hauls. It is greenish 
in colour, and of fine flocculent appearance, and is in 
constitution a phyto-plankton (see fig. 7) almost entirely 
composed of oceanic Diatoms, chiefly species of 
Rhizosolenia (RR. semispina 44 milhons, &. shrubsolu 
1 million and R. stolterfotht 7 to 8 millions), and of 
Chaetoceras (about 5 millions). There are also about 
30,000 Peridinians, and a very few small Copepoda, but 
the larger Copepods characteristic of the vertical hauls 
are entirely absent. It is evident that the larger Copepoda 
(Calanus) are in the deeper water and the Diatoms on the 
surface. A vertical haul from 83 fathoms, taken off 
Mount Erins, further up Loch Fyne, on that same date 
in July, 1908, shows the same type of gathering as the 
vertical hauls off Skate Island. 
It is clear that the Calanus population extends in 
the deep water along the length of Loch Fyne, as hauls 
taken at various points in Upper Loch Fyne, both in 
1908 and 1909, from depths of 54-70 fathoms show the 
same type of plankton as those taken off Skate Island. 
On the other hand, in working down the channel towards 
Bute, Arran and Kilbrennan Sound, we find that the 
gatherings are of a more varied nature. One off Sannox, 
Arran, on August Ist, 1910, from 70 fathoms, is a mixture 
