52 



flkin which more or less covers the body, and is called the mantle. 

 This organ has glands which secret the solid matter of which the 

 fihell is built and by which it can be repaired when damaged. 

 Many moUuses — the oyster, for instance — have no head, whilst 

 others, such as the snail, are favoured with that most useful mem- 

 ber. The headless fellows are, as you might infer, of lower organ- 

 ization than their brethren, and they are aquatic animals with a 

 shell composed of two pieces. We have no bivalves on our coast 

 except common ones. You will at once think of the cockle, the 

 mussel, the scallop, and perhaps also of solen and two or three 

 others. The two valves of the shell are hinged and are controlled 

 by powerful muscles. The scallop " flies " through the water by 

 opening and closing the valves ; the mussel anchors itself to the 

 rocks by means of extremely tough fibres called a byssus, while the 

 cockle and the solen bury themselves in the sand. 



The cockle has a foot, and is able to leap gaily across the mud. 

 I have not yet been fortunate enough to catch the fellow in the 

 very act. The solen works itself with great rapidity into the sand, 

 often to a depth of a foot or more. The most interesting of our 

 bivalves is the pholas. This creature is able, somehow, with its 

 slender shell to bore holes not only in the clay but also in rock. 

 The holes in which the animal Uves and dies, are not of uniform 

 diameter, but are suited to the shape of the shell 



Lastly we arrive at the univalves. The animals are gasteropods 

 or stomach-footed. Examples are the whelk, the famihar "winkle," 

 the purpura, and the dog whelk. Thousands of empty whelk shells 

 are thrown up on the beach, and the living animals inhabit our 

 rocks. The purpura claims notice as the animal from which the 

 rich purple dye was obtained long years ago. 



The limpet is a univalve without a spire. It fixes its shell most 

 firmly to the rocks by creating a vacuum, and so bringing into play 

 the pressure of the atmosphere, which, as you know, is no trifle. 

 Only a word more need be said, and it is this: Some goodwill 

 ■come out of our meeting this afternoon if there is stirred up within 

 us a desire to dnow more about " The wonderful works of God." 

 It was kind of Mr. Ullyet to entitle this paper " Some of the 

 common objects of our shore." Only a few have been noticed. 

 *' The harvest truly is plenteous." 



