MOLLUSCA INJURIOUS TO FARMERS AND GARDENERS. 207 



H. virgata is one of the species that has given rise to the popular 

 notion that snails come down in the rain. It is an extremely 

 abundant and gregarious species, and may be seen in damp 

 weather in vast numbers clinging to the plants. Directly the air 

 becomes dry it retires into the ground amongst the herbage, and 

 there remains hidden until fresh rain comes, when it suddenly 

 reappears. In dry weather it becomes dispersed by the wind, 

 particularly on the downs and sandy heaths, and especially along 

 the sea-coast. Although, as above shown, it sometimes does much 

 harm it is said to have the redeeming quality of imparting a fine 

 flavour to our south-country mutton, being taken up by the sheep 

 when grazing, and considered to be very nutritious. There is no 

 doubt of that, though I very much doubt if they flavour the meat. 

 H. virgata is active in the coldest weather and does not hibernate. 

 During the past cold winter I found, on the down at Wye, 

 several of this species quite active. Eggs are laid in clusters of 

 three or four from September to November and even in December. 

 The shell is conical, with a broad and convex base, white or 

 creamy, with a single purplish-brown band above the periphery, 

 and sometimes as many as six or seven below it, more often two 

 or three : the colour is very variable, sometimes plain white, 

 brown, or grey, with white bands ; occasionally the dark bands 

 are broken, so as to make the shell appear spotted ; whorls 6, last 

 == J-shell ; mouth purplish inside, with a strong rib, sometimes 

 purple, sometimes white. Several varieties are known. The body 

 of this snail is dusky grey, and coarsely tubercled ; mantle dark 

 violet, speckled with white and brown. 



H, caperata is a sluggish species which seldom moves 

 except after rain. It is found generally under stones and wood, 

 and on grass stalks in dry places. It is very abundant often in 

 corn-fields. At Wye last year it was observed in large numbers 

 with H. virgata. The ova, round, white, and opaque, 

 are laid in September and October, each snail de- 

 positing about forty, which hatch in three weeks. The 

 young are quite transparent. I have seen it doing 

 much harm in France. H. caperata differs from H. virgata in 

 its much smaller size, its flattened spire, its larger umbilicus, and 

 the rib-like striae which encircle each whorl. There are other 

 snails which now and then become superabundant to do harm, but 

 so far as my experience goes they are of exceptional occurrence* 



