184 LIMNEA. 



6. ViTEiNA. Heliciform, hyaline. Fig. 262, 263. 



LIMACIISTEA. Bl, The third family of the order PulmobrancHata, 

 Bl. Described as contaiaing shells very variable in fonn, most 

 frequently incliniag to globular or oval ; the apex always obtuse ; 

 aperture variable, but never emargiaated. AU the Limacinea 

 are phytophagous and terrestrial. This family ansvs^ers to the 

 genua Helix of Linnaeus and to the Colimaeea of Lamarck, 

 leaving out the Auriculacea. It contains the genera Succinea, 

 BuHnus, Achatina, Clausilia, Pupa, Partida, Helix, Vitriua, 

 Testacella, Limacella, Limax. 



LIMAX. Liunseus. Limacinea, Lam. and Bl. — Bescr. Internal 

 irregular, sub-quadrate, scutiform, crystalline ; apex rounded, 

 indistinct ; epidermis, light brown, thin, extending beyond the 

 margin. — Obs. The shell is placed under the scuteUum of the 

 common garden slug. L. Antiquorum. PL xiii. fig. 259. 



LIMNACEA. Bl. The first family of the order Puhnobranchiata, 

 Bl. The shells of this family are described as thiu, with the 

 outer lip always sharp. It contains the genera Limnea, Physa, 

 Planorbis. 



LIMISTEAIS'A. Lam. A family of the order Trachelipoda, Lam. 

 contaiaing the following genera :• — 



1. LiMN^A. Spire produced ; including Physa. Eig. 308 



to 310. 



2. Planoebis. Spire orbicular ; including Planaria. Fig. 



311, 312. 

 LIMNEA. Lamarck, 1801. (At/xj^ae, limnas, lacustrine.) Eam. 

 Limnacea, Lam. and Bl. — Bescr. Oblong, light, thin ; spire 

 variable in length, acute ; last whorl large, aperture large, 

 longitudinal, entire ; inner lip spread over a portion of the last 

 whorl ; columella forming an oblique fold ; outer lip rounded at 

 each extremity, thin. — Obs. These light horn-coloured shells are 

 common in standing pools, ponds and ditches, in various parts 

 of Europe. They resemble the Amber shell (Succiuea) in shape, 

 but the animal of the latter is amphibious, and the sheU. of a 

 bright amber colour. L. Stagnalis, fig. 308. L. auricularia, fig. 

 309. (E-ADix, Montf.) The reversed species have been separated 



