LESSON 47.] NUTRITION IN THE GASTEROPODA, ETC. 



163 



land species (Snails and Slugs) feed on the nutritive vegetables of 

 the earth ; many of the marine kinds (Doris, Eolis, Tritonia, &c.) 



FIG. 263. 



The short, narrow 



03- 



FIG. 264. 



Eolis Inca. 



on the lowest fuci of the Sea ; whilst many others are carnivorous, 

 and feed on living prey, 



712. The Aplysia 

 faciata feeds on coarse 

 marine plants, and like 

 the herbivorous quad- 

 rupeds, presents a com- 

 plicated condition of 

 the alimentary appara- 

 tus. The broad labial 

 tentacula (a, Fig. 264) 

 are moved by strong 

 muscular bands (b). 

 The lips are supported 

 by two cartilaginous 

 (gristly) laminae (or 

 plates), and the tongue 

 is covered with minute 

 recurved teeth. 



713. The wide 

 muscular cavity of the 

 mouth (c) receives the 

 terminations of two 

 salivary glands (e). 



sophagus (d) dilates in- 

 to a large membranous 

 crop (i) ; this crop, or 



paunch, occupies the Nutriment* organs, Aplysia faciata. 



right side of the abdomen and opens laterally into the smallest, 

 middle stomach (&), which *is provided internally with numerous 



