THE SHIPWOKM. 105 



the sea-covered portions of wooden piles, and it is a notable 

 fact that the burrows are always made across the grain of the 

 timber in which it Hves. 



Those who are fond of wandering on the sea-shore, will often 

 have experienced tangible proofs of the existence of another bur- 

 rowing mollusc, the Eazoe Shell {Solen ends). 



In some parts of our coast it is impossible to walk on the 

 mixed rock and sand, when the tide has receded, without noticing 

 innumerable jets of water, which start from the ground with- 

 out any perceptible cause, leap for a foot or so in the air and 

 then disappear. On watching one of these miniature fountains, 

 and looking at the exact spot whence it proceeds, two little 

 round holes are generally seen in the sand, so close to each other 

 as to resemble a keyhole, and large enough to receive an ordinary 

 goosequilL If the finger be placed on the spot, or even if the 

 foot descends heavily on the ground, the curious object vanishes 

 far out of the reach of a probing finger. The jets are thrown 

 up by the Solen, and the two little holes are the open extremi- 

 ties of the siphon, that wonderful instrument through which the 

 creature obtains its nourishment. 



If a Eazor Shell should be required for any ordinary purpose 

 such as baiting fishing-hooks, it can easily be procured by push- 

 ing into the hole an iron rod turned up at the end, and twisting 

 the Solen out of its burrow. If, however, a perfect specimen of the 

 animal or shell be required for scientific purposes, it can be ob- 

 tained by the simple process of dropping a spoonful of salt down 

 the hole. The Solen has a strange hatred of salt, and as soon as 

 the obnoxious substance is felt, up comes the Eazor Shell in a 

 hurrj', thrusting itself out of the hole, and enabling the operator 

 to seize it before it can again withdraw to its shelter. 



The curious group of molluscs called Gastrochsenidae, deserve 

 a passing notice. All the species of this family are burrowers- 

 and some of them are capable of making their way through sub- 

 stances of considerable hardness. A common British species, 

 the Flask Shell {Oastrochmna modiolina), is notable for its 

 habit of burrowing through various shells, those of the oyster 

 being often perforated and fixed to the creature by some natural 

 cement. In such cases, the animal constructs a flask-shaped case 



