MOLLUSCA 



earthy matter) than those of marine mollusks, having 

 to be carried on the back without the support of the 



FIG. 92. A, Land Suail (Helix)', B, C, D, Slugs (Limax}; E, F, G, Pond Snails 

 (Lzmnaa, Paludina, and Planorbis). 



water. Their eggs are laid singly, while the eggs of 

 other orders are laid in chains. 



They are found in all zones, but 

 are most numerous where lime and 

 moisture abound. All feed on vege- 

 table matter. A few are naked, as 

 the slug ; some are terrestrial ; others 

 live in fresh water. The land snails, 

 represented by the common Helix, the 

 gigantic Bidimus (Strcphocheilus), and 

 the slug (Limax), are distinguished by 

 their four "horns," the short front pair FIG. 93. &> 

 being the true tentacles, and the long 

 hinder pair being the eye stalks. They 

 have a sawlike upper jaw for biting leaves, and a short 

 tongue covered with minute teeth. The pond snails. 



Guiana - 



