440 A DESCRIPTION OF 
prickles, and the colour of the whole is elegantly variega- 
ted. 
- THE WHELK (Bucdnium undatum,) 
Is used by the labouring people as an article of food, but 
it is of the coarsest description. The shells are not re- 
markable for their beauty, but they are delicately formed. 
The Whelk is common on all the shores of Britain. 
THE LIMPET. (Patella.) 
THE shape of the shell is pyramidal ; it adheres to the 
rock with such strength, that no human force can make 
it leave its hold, unless it is crushed by a strong blow. 
The apex of the shell is sometimes sharp, sometimes 
obtuse, and often surrounded with points and sharp 
prickles. When cleaned by proper means, the shell is 
generally found of a beautiful purple tint, which some- 
times emits rays of reflected light of an uncommon bril- 
liancy. They are found on the rocks, which are inces- 
santly beaten by the surges and breakers, on the sea- 
shores of almost every country in the world. The rays 
of variegated colours, which issue from their tops, are 
sometimes found of the most vivid hues ; and the animal 
that lives under this magnificent roof, or versicolored 
canopy, is a kind of snail, disagreeable to the eye, and in- 
