246 



then perhaps habited in the same manner as ihejield 

 moths. 



14. We do not expect to make any material disco- 

 veries from sh ell-Jish that are shut up in an almost 

 stony inclosure ; they seem very stupid ; but they are 

 not a!4 so senseless as they appear to be : we shall with 

 pleasure contemplate the proceedings of some of them. 



Divers species of sea shell-fish are furnished with two 

 pipes, by means of which they suck in the water, and 

 which they take great care to keep raised above the 

 vessel they are accustomed to sink into more or less. 

 Some spurt out the water to the distance of several feet. 

 That particular part which in some performs the pro- 

 gressive or retrograde motion, very much resembles a 

 real leg with a foot joined to it; but this leg is a Pro- 

 teus, which assumes all kinds of forms to supply the 

 necessities of the animal. It does not only make use of 

 it to crawl with, sink into a vessel, or retire from it; 

 but employs it with much greater skill to perform a 

 motion that one would not imagine a shell-fish capable 

 of. A shell-fish that leaps, must appear very extraordi- 

 nary : it is a tellina that you are now seeing. You may 

 observe that she has placed the shell on the top, or 

 point. She stretches out her leg as far as possible; she 

 causes it to take hold of a considerable part of the cir-, 

 cu inference of the shell, and, by a sudden motion, simi- 

 lar to that of a spring that is slackened, strikes the 

 ground with her leg, and thus leaps to a, certain dis- 

 tance. 



15. The cutler never creeps: it penetrates perpen- 

 dicularly into the sand. It there digs itself a sort of 

 cell, which is sometimes tw r o feet long, in which it goes 

 up and down at pleasure. Its shell, whose form a little 

 resembles that of the handle of a knife, has occasioned 

 it to receive the name of cutler: it is composed of 

 two long pieces, hollow like a gutter, and joined toge- 



