654 
Proceedings of -the Eoyal Society 
shaded portion of the above diagram (2) 1 Does any of it pass over 
the ridge to the west ? What becomes of the excess of this cold 
water? At present we can give no satisfactory answer to this 
question. A discussion on this point may appropriately be deferred 
till the further observations and more detailed investigations which 
it is proposed to undertake during the present season have been 
completed. 
Bearing in mind the peculiarity pointed out above as existing 
in the Faroe Channel, the doctrine of submarine barriers may be 
stated in more general terms than those used on page 4, as 
follows : — A divergence of temperature between the deep waters of 
two contiguous areas of the ocean indicates the level of the lowest 
point of the ridge of a submarine barrier separating the two areas. 
4. Surface Dr edgings by means of the Tow-net. — During each of the 
trips the tow-net was worked from the ship whenever the weather 
would permit. For several days Acanthometroe were enormously 
abundant at, and for several fathoms beneath, the surface : during 
our last trip to the cold area very few of them were met with. 
Pelagic foraminifera had never been taken near the British Islands, 
but relying on our “ Challenger ” experience, we predicted that they 
would be captured in the tow-net so soon as the water beyond the 
Butt of Lewis was reached. Our anticipations were realised. So 
soon as we got into true oceanic waters globigerinm were procured in 
considerable abundance at the surface. Orbulinse were rare, and we 
only noticed one Pidvinulina micheliniana. All these specimens 
were dwarfed, and quite similar to the dead shells found at the 
bottom both with regard to their size and relative frequency. These 
observations were quite in accordance with those made by the 
“ Challenger ” in various parts of the world. The occurrence of 
these surface forms in the deposits of the cold area shows that the 
upper layers of water are passing to the north-east; while Globi- 
gerina borealis , wdiich we believe to be an arctic surface species, does 
not apparently occur in the w r arm area deposits, this would seem to 
show that the arctic water does not pass over the ridge to the south- 
west. 
On one occasion, several miles off the Butt of Lewis, we spent 
some hours in examining a portion of the sea where numerous puffins, 
gannets, razorbills, and other birds were feeding, one of those 
