PULMONKA ; SLUGS, SNAILS. 



371 



it. The Testacella is a kind of slug which has the disc 

 of the mantle at the posterior extremity, and this always con- 





FIG. 5(J3. TESTACELLA. 



tains a small shell. This animal, which feeds largely on earth- 

 worms, is abundant in the south of France, and has lately been 

 introduced into the gardens of this country, where it is multi- 

 plying rapidly. 



913. The Snails and their allies, constituting the family 

 HELICINJE, are closely allied to the Slugs in organisation ; differ- 

 ing in but little else than the possession of a shell, into which the 

 body may be withdrawn. The Common Garden-Snail of this 

 country, and the Helix pomatia, or Edible Snail of France and 

 k , a t > p r Italy, are well- 



known examples 

 cv of this family. 

 More striking ones 

 are to be found, 

 however, in tro- 

 pical climates. 

 Among the mem- 

 bers of this group, 

 we may especially 

 notice the genus 

 Anastoma, which 



FIG. 564. ANATOMY OF SNAIL; /, foot; t, tentacula half is distinguished by 



contracted ; d, a sort of diaphragm, separating the respira- ,1 ,i; fnrrn 



tory cavity from the other viscera ; #, portion of the sto- ll 



mach; I, liver; o, ovary; /, intestine; r, rectum, or last and position of the 

 part of the intestine ; a, anus ; h, heart ; ap, pulmonary f . . 



artery, distributed over the walls of the pulmonary cavity, mouth 01 the Shell 



p; ar, aorta; v, secreting gland for the mucus which J n the adult Dlir 



covers the body ; cv, its excretory duct, opening near the " 



anus. ing its early life, 



its mouth is in the same position as that of other snails; 



