MOLLUSCA. 27 
Of those species which dwell upon the land and 
breathe the air, most affect moist situations. The 
common Garden Snail, as is well known, retires to 
crevices and corners in continued dry weather, 
where it closes its shell with a temporary door to 
prevent the evaporation of its vital juices, and 
patiently waits the return of congenial humidity. 
The first shower prompts the sensitive creatures to 
venture abroad, and we see them crawling by 
dozens over our borders and garden walks, im- 
bibing from the steaming surface the grateful mois- 
ture. The damp woods of warm countries are the 
situations which most reward the researches of the 
laborious collector of land-shells; but there are 
some which are found in the driest places, as stony 
plains, and the summits of arid hills. 
GARDEN SNAIL. 
Many terrestrial Mollusca which ordinarily in- 
habit moist places, are enabled, by a precaution 
similar to that adopted by our own Snail in 
