SEA FISHERIES LABORATORY. 107 
in some places. The action of this animal is of im- 
portance in the first place in forming a protection to 
the land by binding together the loose sand on the beach 
and in shallow water beyondit; and secondly the irreg- 
ular masses and reefs constitute a sheltering place, 
and serve as points of attachment for many kinds of 
animals and consequently as a favourite feeding ground for 
many others. Prawns there is little doubt are specially 
abundant and large in the neighbourhood of Sabellaria 
banks. They are said to hide in the crevices between the 
‘tubes. This may be so, but probably the food they get 
there is of more importance as an attraction; and I have 
little doubt that the great masses of Sabellaria tubes are 
an important feeding ground for various kinds of fishes, 
both in young and adult stages. 
SURFACE LIFE. 
The surface fauna of the sea in our district, as made 
known by the microscopic examination of the stuff caught 
in the tow-nets, has been specially investigated during the 
dredging expeditions of the Liverpool Marine Biology 
Committee, and is found to vary much both in nature and 
in amount from time to time and from place to place. 
Often for weeks together in spring the surface waters seem 
to contain very little but Diatoms. These however are in 
great profusion, and form the food of many animals which 
in their turn are eaten by fishes. Later on the Diatoms 
sive place to swarms of Copepoda, and the larval stages of 
many invertebrates. Sometimes one particular species of 
Copepod will form almost the whole of the tow-net gather- 
ing in a particular locality. This is sometimes the case 
with the large forms Calanus finmarchicus and Anomalo- 
cera patersonw. Under such circumstances the very great 
abundance of the one form of animal is astonishing, the 
