ALLIES OF THE ACEPHALA 



211 



The Land Snail. One of the commonest of the land snails 

 in America is the one shown in Fig. 113 (Polygy'ra). The 

 many species of the genus Polygyra live in moist, protected 

 places during the day and come out to feed at night. Fre- 

 quently they leave their 

 hiding-places in cloudy, 

 damp, but not in rainy, 

 weather. 



) The organs to 

 be noted on the 

 exterior of this animal are 

 the same as in the pond snail. The 

 openings of all the internal organs 

 occur in the same position in both 

 animals. There are four tentacles 

 in this land snail, — an upper, long 

 pair bearing the eyes, and a lower, short pair, which are 

 the organs of touch. The edge of the mantle is thickened 



to form a collar. 



The Garden Slug. The particular species of garden slug 

 of which the habits are suggested in Fig. 114, is Li' max 



Fig. 114. Garden slug feed 

 ing at night. (X \ ) 



