LAND SNAILS. 19 



crawling, and then their resemblance to the shell-bearing 

 snails will be seen at once. 



Instead of having a coiled shell into which they can 

 retreat when alarmed, they have a little limy scale imbedded 

 in a portion of the back, called the mantle. The breathing- 

 orifice is on the right side of the body, and the tentacles, 

 mouth-parts, creeping disk, and other features, are quite 

 similar to the land snails already studied. 



FIG. 22. A NAKED LAND SNAIL, OB SLUG, FULLY EXPANDED. a. Mantle ; ft, Breathing- 

 Orifice. 



18. On the approach of winter, land snails bury them- 

 selves in the ground, and those that have shells retire within 

 the shell as far as possible, and close the aperture of the shell 

 with a film of the mucus which the body secretes so abun- 

 dantly. In this condition they remain dormant until re- 

 vived by the warm weather of spring. 



If the pupil will collect a number of snails in the early 

 spring, and keep them confined in a box, with earth, damp 

 leaves., or bits of rotten wood or bark, the snails in the course of 

 a few weeks will lay a number of little eggs. These eggs will 

 be white and round, about the size of a pin's-head. By care- 

 ful tending, that is, by keeping the leaves slightly moist, the 



