PULMONEA ; SLUGS, SNAILS. 



371 



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

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



ap p 



FIG. 563. TESTACBLLA. 



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 

 HELICIN^E, 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 body may be withdrawn.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 



Italy, are well- 

 known examples 

 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 y f 



tory cavity from the other viscera ; *, portion of the sto- l 



mach; I, liver; o, ovary; i, intestine; r, rectum, or last and position oftlie 

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



artery, distributed over the walls of the pulmonary cavity, mouth of the shell 

 P-, ar, aorta; v, secreting gland for the mucus which Jntheadult Dur- 

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



anus. ing its early life, 



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



