250 PERIWINKLES AND MUSSELS. 



was elevated in the water, the sound was like the snap of a 

 finger, and the water was splashed in my face." 



The same authority called this animal the " trigger " 

 shrimp, from the action of this claw resembling that of a 

 pistol trigger. If only put upon half-cock, this trigger closed 

 without noise. 



How wonderful are the means that the Omnipotent Cre- 

 ator has provided (as in all things) for the protection of the 

 shelly inhabitants ! The hard covering accommodates itself 

 to their growth, and at the same time is sufficiently light as 

 not to interfere with the m_ vements and functions of the 

 interesting tenant. All the various tribes of shell-bearing 

 animals are thus defended from the injuries and attacks to 

 which their situation exposes them. Thus, some are pro- 

 tected by multivalve, or more than two formed tubular shells, 

 the tenant protruding its organs at the summit, which is 

 defended by the lid, consisting of more than a single piece ; 

 in the univalve, or one shell, the animal protrudes itself at 

 the sides, and has no valve, as in the common barnacle. The 

 bivalves, or animals of two shells, bury themselves in the 

 sand, perforate rocks, or suspend themselves by the byssus, 

 or thready filaments; others, again, as the oyster, fix them- 

 selves to any convenient substance. 



In the common Periwinkle (a molluscous, or soft-shelled 

 animal), the mouth of its shell is closed by a horny cover- 

 ing ; this is called the " patch," which is attached to the foot, 

 or rather neck, by its convex or lower surface : this is the 

 lid. 



The Mussel, belonging to the molluscous animals, and the 

 common species of which are very abundant on our own 

 and English coasts, are much used as bait by fishermen. 

 As an article of food it is much consumed in our own country, 

 but especially so in Europe. The French people are remark- 

 ably clever in their method of cultivating this shell-fish by 

 artificial means. About four miles from Roclielle there may 



