156 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
large numbers of Nitzschia seriata, of Rhizosolenia 
stolterfothi, and of Thalassiosira gravida. 
Again, the six hauls taken in Loch Hourn (see p. 151), 
off the Sound of Sleat, a ttle further up the coast, and 
the three taken in the closely adjacent Loch Nevis, are 
all much alike in character but differ from those off Mull; 
consisting, as they do, of comparatively small catches 
not green in colour, chiefly made up of zoo-plankton and 
composed mainly of small Copepoda, some young 
Nyctiphanes, Sagitta, Polychaet larvae and many 
Tintinnide and Peridinians (especially in 1909), along 
with some Diatoms. The gatherings taken inside these 
neighbouring lochs on the mainland contrast markedly 
with hauls taken at the same time of year in the open 
sea further west, e.g., off the Islands of Canna and 
Rum. A vertical haul from 85 fathoms on July 19th, 
1910, between Eigg and Rum, and another on July 14th 
from 128 fathoms, between Canna and Rum, show well- 
marked green-coloured phyto-plankton; and other hauls 
off Canna on July 13th and 14th in the same year, from 
depths of 80, 105 and 130 fathoms, are also characteristic 
phyto-plankton gatherings composed chiefly of common 
species of Chaetoceras. The contrast between such a green 
Diatom haul taken in the sea of the Hebrides off Canna, 
in July, and a similarly captured haul at the entrance to 
Loch Fyne at the same time of year is most marked, the 
first being a typical fine phyto-plankton (such as fig. 8), 
and the latter a typical coarse zoo-plankton (fig. 6). 
As we have shown above, two such gatherings if obtained 
in the Irish Sea would be regarded as characteristic of 
two distinct seasons of the year, months apart. The 
difference between the Diatom hauls in the open sea and 
the fine zoo-plankton hauls in the deep fiords running 
into the mainland, such as Loch Nevis and Loch Hourn, 
is not so marked, but is still quite noticeable. 
