106 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
shown that in some parts of our district, generally a con- 
siderable distance off shore, the fauna at the bottom is 
exceedingly abundant. Dredgings from depths of about 
20 fms., at 25 miles N. W. of the Bar Light-ship, bring up 
such masses of Ophiuroids (chiefly Ophiocoma mgra, and 
Ophiothria pentaphyllum), that the dredge net has more 
than once been choked to the mouth; and this has hap- 
pened on several successive hauls, showing that this 
astonishing abundance of life extends over a considerable 
area. This must be an important feeding ground for 
Haddocks and Dabs, as we know that Ophiuroids form a 
large part of the food of these fishes. Then in other parts 
of the area off-shore, and in some places between the 
banks the dredge brings up abundance of Lamellibranch 
Molluses—such as Scrobicularia alba, Tellina balthica, 
Mactra subtruncata, and especially Mactra stultorwm; 
and these we know from our investigations in the labora- 
tory are a very important constituent ofthe food of Plaice, 
and to a less degree of the Haddock. Then again at a 
spot 25 miles N. W. of the Liverpool Bar, depth 21 fms., 
the dredge has brought up great numbers of the Annelid 
Onuphis conchilega,.and this and other Annelids are a 
favourite food of Soles, Plaice, &&. Amongst Zoophytes, 
Polyzoa, and Algee in shallow water we frequently find 
enormous quantities of Amphipoda and other smaller 
Crustacea which we know to be the food of young Cod, 
Whiting, and other valuable fishes. 
Another invertebrate which although not itself market- 
able is indirectly of great economic importance is the gre- 
garious annelid Sabellaria alveolata which builds up the 
loose sand grains into firm masses of adhering tubes 
known locally by the fishermen as “‘ ross’ and ‘“‘ knarrs.”’ 
These masses form hummocks, reefs or banks which 
extend for hundreds of yards or it may be even for miles 
