MOLLUSCA. 815 



t Aperture turned upwards, dentate on each side. 

 Anostoma FISCHER, LAM. 



Sp. Helix ringens L., D'ARGENV. Conchyl. PI. 28, figs. 13, 14, BLAINV. 

 Malac. PI. 39, fig. 4; habit, in E. Indies 1 . 



*f* "t 1 Aperture inclined downwards, shell at the periphery carinate or sub- 

 carinate, mostly depressed. Ldbrum often reflected, sometimes dentate. 

 Carocolla LAM. 



Sp. Helix Lapicida L., PFEIFFER Schn. i. Tab. n. fig. 26; Helix Carocotta 

 L., D'ARGENV. Conch. Tab. 8, fig. D, GU^RIN Iconogr., Moll. PL 6, fig. i ; 

 from the E. Indies, &c. 



1 1 1 Aperture inclined downwards. Shell rounded at the margin, most 

 frequently subglobose. 



Helix LAM. 



Sp. Helix Pomatia L., STURM Deutschl. Fauna, vi. Heft i, PFEIFFER Schn. 

 I. Tab. II. fig. 9, Cuv. R. Ani., ed. ill., Moll. PI. 21. The Vineyard-Snail, le 

 grand Escargot. The name Pomatia, from IIwyu,a, cover (cochlea opercularis), 

 was given to this animal on account of the closure of the aperture of the 

 shell in winter that occurs in this and other species. In autumn the animal 

 retracts itself within the shell, and then a false operculum (epiphragma) is 

 secreted, which is pushed off in spring when the snail again creeps out of 

 its house. During the winter these snails in our temperate climate take no 

 food, but lie asleep ; in like manner, in tropical regions the species of this 

 genus in the dry months fall into a state of insensibility. 



For the anatomical particulars we refer to SWAMMERDAM Bijbel der Nat. 

 i. pp. 97 147; CUVIER Ann. du Mus. vn. 1806, pp. 140 184, Mollusq., 

 Mem. No. 1 1 ; and WOHNLICH Diss. anat. de Helice pomatia cum tab. cen. 

 Wirceburgi, 1813, 4to. In all the species of Helix there is found in the 

 neighbourhood of the sexual organs a thick-walled pear-shaped purse, in 

 which a dart-shaped calcareous stile is contained ; this organ is annually 

 renewed, just like the cover of the mouth of the shell. 



Helix adspersa MUELL., STURM Deutschl. Fauna, vi. Heft vi. Tab. 4 ; 

 this species nearly attains the size of the preceding; Helix nemoralis L., 

 STURM 1. 1. Heft 2, &c. On this and other native species, the figures of 

 PFEIFFER and STURM may be compared. This genus is also remarkably 

 numerous in exotic species. 



Succinea DRAP. Animal larger than shell, not entirely covered 

 by it, with four tentacles short, especially the inferior. Shell ovate, 

 with spire short ; aperture ample, longitudinal, with labrum acute, 

 columella short. 



1 Some fossil shells from the tertiary formations are known, which also have an 

 aperture turned upwards ; but this is round and not toothed. They form the genus 

 Strophostoma DESHATES, and might be brought to Cydostoma (p. 801). See DESHAYES 

 Mem. sur le Strophostome, Ann. des Sc. nat. xni. 1826, pp. 282287. 



