FAMILY Ml. 

 HELICID^. 



THE SNAILS. 



Chakacters. Animal. Having the body divided 

 into two distinct parts ; the one consisting of a mem- 

 branous sack, and including most of the viscera, is 

 arranged in a spiral form within the convolutions of 

 the shell ; the other comprising the head, the anterior 

 portions of the organs of digestion and generation, and 

 the locomotive disk, is elongated, sub-cylindrical, covered 

 with a glandular membrane, and resembles in its external 

 characters, the animals of the family of Limacida; ; it 

 can be retracted entirely within the shell. The junction 

 of the two parts is encircled by a fleshy contractile pro- 

 cess or collar which is expanded into, and fills up, the 

 aperture of the shell. Tentacles foui", the two superior 

 long and cylindrical, terminating in bulbs containing the 

 ocular points ; the two inferior short, and more or less 

 conical. In some of the genera there are buccal appen- 

 dages, or prolongations of the external membrane near 

 the mouth, of various shape, but in the genus Glandina 

 taking an elongated, curved form, resembling a third 



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