64 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



they would be less liable to be washed away, when once 

 they had securely attached themselves to the twigs. 



There is a small mussel bed at Mort Point near the 

 Piel end of Baicliff cockle bed. The mussels on this bed 

 appear to represent two stages of growth. On the inner 

 part of the scar, where the bottom is largely composed of 

 stones, the mussels are from 1J inches to 2 inches in 

 length but are covered with the elongated variety of Bala- 

 nus crenatus, Brug., in some cases to such an extent as 

 to leave little of the mussel shell visible. The outer part 

 of the bed, that nearest to the sea, is covered with a set 

 of young mussels ranging from f of an inch to 1^ inches, 

 but the larger size are comparatively scarce. The mussels 

 here, are not unlike those on the outer scar at Roosebeck. 

 The shells are quite free from barnacles, which seems to 

 be commonly the case with mussels which are only 

 exposed during the ebb of spring tides. Mussels, stones, 

 wooden posts, &c, which are exposed to the air at every 

 ebb appear to be more frequentty covered with barnacles, 

 than is the case with similar objects only seldom exposed. 



The presence or absence of barnacles upon mussels is 

 no guide to the quality of the fish inside, but the scars 

 left when they have been cleaned off give the shells an 

 unsightly appearance, and so may affect their sale. 



Cockles and Cockle Beds. 



The work carried out during the past year in connection 

 with the investigation into the food, spawning time, and 

 other points connected with the life-history of the cockle, 

 has been on similar lines to those on the mussel. 



The constituents of the food supply of this shellfish are 

 in all points similar to those that the mussel feeds upon, 

 and consist chiefly of diatoms, spores of algfe and other 

 vegetable remains. 



