( 62 ) (Pulmonacece.) 



5. HelicArion. Fe7ws. 



Body truncated behind, 

 with a cuirass in front, 

 under the anterior edge 

 of which it retires its 

 head : shell posterior ; 

 foot separated from the 

 body by a furrow and 

 with a mucous pore at its 

 extremity. PI. 14, fig. 7. 

 PL 16, fig. 6. 



6. Helix. (1) Lin. 



Body with a muscular Mantle forming a kind Head indistinct, with 

 disk or foot, sometimes of ring or collar (at the two pair of retractile 

 pediculated, more or less point of junction of the tentacula, the posterior 

 gibbous and spiral above, two parts of the body), the larger, and bearing 



in which is pierced the the eyes at the summit ; 

 round orifice of the re- mouth with a pair of 

 spiratory cavity. short appendages. 



a. Bulimus, Lam. (2) 



b. Pupa, Lam. 



c. Searabaeus, Montf. 



d. Chondrus, Cuv. 



e. Amphibulima, Lam. (3) Inferior tentacula very small. 



f. Clausilia, Drap. (4) 



g. Achatina, Lam. (5) 



(1) V. p. 74. 



(2) Large and beautiful species are found in warm countries : some are remark- 

 able for the size of their eggs, the shell of which in stony ; and others for their sinis- 

 tral shell. The Helix decollata has the singular habit of breaking the whorls at the 

 top of its spire, proving that the muscles of the animal can detach themselves from 

 the shell without injury, and that they adhere to different points of the shell suc- 

 cessively. How is it that they thus effect the separation of the vessels from one 

 part to implant them in another? for it sometimes happens that this Helix or Bu- 

 limus has but one of the original whorls of its spire left. Some species of Pupa, 

 Clausilia, and Mclania are found in the same state. The Kambeul of Adanson ap- 

 pears to pass the dry season in a deep trance, like the Limax of Europe, for he 

 found several half buried after the month of September. Some had even already 

 began to close the mouth of their shell with a whitish plastery matter, to defend 

 themselves from the long drought, which continues at Senegal from October to the 

 following J une. 



(3) This animal may perhaps be considered as a Testacella with a large shell. 

 Its inferior tentacula are very small, and it lives on herbs and bushes by the side 

 of streams, which has caused it to be thought an amphibious genus. 



(4) In the narrow part of the last whorl we generally find a small plate, slightly 

 curved like an S : its use to the animal is unknown. 



(5) At the extremity of the truncated columella we find the first indication of 

 the notches in the shells of the marine Gasteropoda, 



