39 
Some of the common mollusks on the beds are Cardium edale , 
Solen siliqua, v. arcuata, Tapes pullastra, T. viryinea, Mya arenaria , 
Dosinia exoleta, Lutraria elliptica, Littorina littorea, L. rudis, L. 
obtusata, Purpura lapillus, Buccinum undatum , and Patella vulgata 
on the scaup, and in the other part of the flats, near the slakes 
particularly, Macoma balthica, Scrobicularia tenuis , and Paludestrina 
stagnalis. 
There is certainly much room for transplanting the mussels on 
the scaup, good ground is plentiful, and small mussels which might 
be thus used are abundant. The slakes are apparently not so well 
adapted for the cultivation of mussels, the extremely soft ground 
being a drawback, also the tide being for too long a time off the 
beds. Prolonged frosts materially affect the beds, especially those 
which are uncovered for many hours a day. 
BERWICK-ON-TWEED (see Map VI.). —Mussels occur in the 
Tweed in the bed of the river, on the side opposite the Spittal, from 
below the bridge to the end of the pier, extending from low water 
mark of ordinary tides to about the middle of the river. A few are 
found above the bridge (but these are generally choked by mud) 
and they do not extend out to sea beyond the pier. None are found 
on the south side. The mussels are thus covered by water except 
at the lowest spring tides, and even then there are many still under 
water, which have to be dredged. The bottom on which the 
mussels lie is gravelly mud stretching over the lowest beds of the 
Carboniferous Limestone series, consisting of rapidly alternating 
sandstones, shales, and thin limestones. The mussels are grouped 
in small clusters, with seaweed (Fucus) and small stones attached 
to them, and are a good size (2 to inches long). Those nearer 
low water mark, which are less covered by the tide, are of the 
variety galloprovmcialis, and lie buried in the ground. These are 
small (average size If to 2 inches long), but quite healthy. The 
stomachs were full of food, chiefly vegetable. At the end of 
September they were mostly thin, but the mantles were beginning 
to fill out, which seemed to indicate that the breeding season is over 
by the end of August. 
The only mollusks seen with the mussels were Littorina littorea 
and L. rudis. 
The fishermen take the smaller mussels and transplant them up 
the river, but they still do not have enough for bait, and buy much 
from Morecambe, keeping it in water a little north of Berwick, by 
