SLUGS AND SNAILS. 



301 



Fig, 175. — Testacella. 



the slime is also yellowish. The shell consists of a number of 

 small separate calcareous grains. This species is a scavenger as 

 well as being injurious. 



Another curious group of Slugs 

 belong to the genus Testacella. 

 These molluscs (fig. 175), of which 

 there are three species in England 

 (T. haliotidea, T. scutulum, and T. 

 maugei), feed almost entirely on 

 earthworms, slugs, snails, mille- 

 pedes, &c. The Testacellse are the 

 only true predaceous or carnivorous 

 land mollusca. They hunt earth- 

 worms in their burrows, and de- 

 vour huge lobworms much larger 



than themselves. The mouth is a, resta«Ha Miofufar. .- «. head ; 

 furnished with long curved teeth ^■,^{',"1'' •"'■ ™™ ^ ^' '"'*'• '™' 

 (t), so as to hold the victim. They 



live for four or five years. The eggs are laid separately in April, 

 and resemble hen's eggs in shape, and covered by creamy white 

 calcareous shells. From six to twenty ova are laid by T. halio- 

 tidea. According to CoUinge, they hatch in from fourteen to 

 seventeen days. 



Snails (HELiciDiE). 



The Snails, like Slugs, are nocturnal and crepuscular, seldom 

 crawling about in the daytime, unless after heavy rains. The 

 latter habit has given rise to a popular idea that snails come in 

 rain-clouds. When the breeding season is on, the male organs 

 are supplemented by one or more curious crystalline darts, which 

 they thrust out at one another : these curious structures, found 

 in special sacs called " dart-sacs,'' are peculiar to the genus Helix. 

 The eggs are laid in batches in slanting galleries underground 

 formed by the '' mother " snail : they are white, round, semi- 

 transparent bodies. 



