Il6 A HANDBOOK FOR SOUTHPORT. 



through the water by rapidly opening and closing their valves, 

 the large river mussel pushes itself along with its foot, and the 

 cockle jumps along the sand. The Univalves are provided 

 with a large muscular foot, by which they crawl along the 

 bottom of the sea, or upon aquatic plants and sea-weeds. 

 They have a head, eyes, a mouth armed with jaws, and a 

 tongue, called a lingual ribbon, which is covered with a 

 variable number of minute siliceous teeth. They feed upon 

 confervas, sea-weeds, and zoophytes ; many of them are carni- 

 vorous, attacking each other, and also the quiet bivalves. With 

 their file-like tongue they rasp a small hole through the shell, 

 and then devour the helpless inmate ; this will explain to the 

 shell-gatherer why so many of the shells he picks up on the 

 shore have little round holes drilled through them. The 

 Bivalves live upon the animalcula and microscopic vegetable 

 matter in the surrounding water; it is carried into the digestive 

 cavities of the animal by currents caused by the action of their 

 ciliary apparatus. 



A stranger coming to Southport from one of the inland 

 counties for the purpose of collecting shells, would probably 

 be very much disappointed on his first visit to the shore, as 

 there are certainly very few shells to be found in the imme- 

 diate vicinity of the town. The best collecting ground is from 

 Birkdale to Formby, at high-water mark, and on the banks 

 near low-water at high-water mark during the period of the 

 highest tides, especially after heavy west or south-west gales, 

 and near low- water on the slopes of banks during low tides. 

 It is also well to examine the shore at extreme low-water 

 during the times of the highest tides of the year, as at those 

 parts which are not often left uncovered by the water, Mya 



