36 Beautiful Shells. 
in an old wall, or burrow in the earth, or congre- 
gate beneath garden pots, roots of trees, thatched 
roofs, or in any hole or corner that may be con- 
venient, and then throwing a kind of temporary 
skin, like a drum head, which naturalists call oper- 
culum, over the opening of their shells, and sticking 
themselves fast to the sides of their refuge, or to 
each other, they sleep away, careless of frosts and 
tempests. 
A moist and rather warm state of the atmosphere 
seems most congenial to the land Snails, some 
species of which are found in all countries, except 
those where the most intense cold prevails. Gene- 
rally speaking, they do not like dry heat, and to 
escape from it will get under stones, and into other 
cool places, from whence a shower brings them 
forth in such numbers, the smaller species espe- 
cially, as to lead to the popular belief that it some- 
times rains Snails. 
These Gasteropods, although extremely injurious 
to vegetation, must not be regarded as worse than 
useless, as they commonly are; besides furnishing 
food for several wild, as well as domesticated, birds, 
they are no doubt a nourishing article of diet for 
man. The Romans had their cochlearia, where 
Snails were regularly fed and fattened for the table; 
