SEA-FISHERIES LABORATORY. A57 
applied also to other genera of marine Lamellibranchs, 
both round our own coasts and in America. 
The condition most favourable for the formation of 
a Pecten bed is a shelly bottom, with a little mud. ‘Too 
much fine mud is detrimental. The most favourable 
depths are from five to twenty fathoms, though the species 
occurs sporadically in much deeper water, but not in 
communities. ‘The animal seems to be readily injured by 
a low temperature, and in the year 1895 large numbers 
were killed in the Firth of Forth by the long continued 
cold weather. 
Scallop dredging extends almost throughout the 
year in the Firth of Forth, but very little goes on during 
the time of the herring fishing in summer, and this is the 
time when the shellfish are least valuable, for owing to 
their gaping shells and their habit of clapping the valves 
the sea water cannot be enclosed, as in the mussel or 
oyster, and the animal, consequently, soon dies when 
removed from the water. 
The dredge used for the purpose of clam fishing is an 
oyster dredge of five to six feet in breadth of mouth. The 
net attached to the frame is made up, on the lower side, 
of a series of iron rings laced together with short pieces 
of wire, so that repairs can be very easily made with 
additional rings and wire. ‘The upper side of the net is 
composed of ordinary twine. The clams are mostly used 
for the baiting of long lines, five hundred clams being 
required for a line of one thousand hooks. 
With regard to the value of clam as bait, experiments 
have been carried out by the Scottish Fishery Board, 
from whose reports the figures given have been taken. 
The lugworm (Arenicola) seems to have given the best 
results, though the mussel (Mytilus) and clam (Pecten) 
come close after, and the three are probably about equally 
