156 HELICID^E. 



These little Glass-Snails are allied to the Slugs in 

 some of their habits, and to the true Snails in the form of 

 their shells, leading to the former through Succinea and 

 to the latter through Zonites. Their food is partly vege- 

 table, consisting of Jungermannice and decayed leaves, 

 and partly animal. They are said to attack earth- worms, 

 although not in the same way as Testacellce. I once saw 

 no less than seven individuals of V. pellucida busily en- 

 gaged in feeding on a scarcely dead worm, which was 

 faintly writhing about and endeavouring in vain to get 

 rid of its tiny assailants. They have also been noticed 

 eating horsedung. They live in moist and shady places, 

 but are seldom met with until late in the autumn. Their 

 eggs are deposited in small heaps and have a membranous 

 covering. The whole of the body can be withdrawn into 

 the shell. They are very hardy, and capable of enduring 

 an extreme degree of cold. I have found a variety of 

 the V. diaphana on the Rifelberg near Monte Rosa, at a 

 height of between 7000 and 8000 feet above the level of 

 the sea, living among perpetual snows and on ground 

 that never thaws. Only one species now inhabits this 

 country, although another (V. diaphana) formerly did 

 so, as is proved by its occurrence in our upper tertiary 

 strata. This last species has a wide range over the Con- 

 tinent, and, according to Potiez and Michaud, inhabits 

 the North of France. It has been observed on the 

 Vosges Mountains at a height of upwards of 4000 feet. 

 Several other species are found on the Continent. 



VlTRINA PELLU'CIDA*, Muller. 



V. pellucida, Mull. Verm. Hist. pt. ii. p. 15 ; F. & H. iv. p. 30, pi. cxxxi. 

 f. 8-10, and (animal) pi. I. I. I. f. 2. 



BODY rather slender, grey with more or less of a reddish 

 * Transparent. 



