LIMACINA. Cuv. (_Limax_, a snail.) _Fam._ Pteropoda, Lam.--_Descr._ Papyraceous, fragile, planorbicular, sub-carinated, obliquely convolute; spiral side rather prominent, the other side umbilicated; aperture large, entire, not modified, peristome sharp.--_Obs._ This is SPIRATELLA, Bl. The shell figured as Limacina in Sowerby's Genera, under "pteropoda," is an _Atlanta_. Our representation of Spiratella Limacinea, fig. 224. is copied from Blainville. LIMACINEA. Lam. A family of the order Gasteropoda, Lam. including the following 1. CRYPTELLA. Spire mammillated; a septum. Fig. 256. 2. PARMACELLA. Flat, haliotoid, spiral. Fig. 257, 258. 3. TESTACELLUS. Sub-spiral. Fig. 261. 4. LIMAX. Incomplete. Fig. 259. 5. PLECTROPHORUS. Conical. Fig. 260. 6. VITRINA. Heliciform, hyaline. Fig. 262, 263. LIMACINEA. Bl. The third family of the order Pulmobranchiata, Bl. Described as containing shells very variable in form, most frequently inclining to globular or oval; the apex always obtuse; aperture variable, but never emarginated. All the Limacinea are phytophagous and terrestrial. This family answers to the genus Helix of Linnæus and to the Colimacea of Lamarck, leaving out the Auriculacea. It contains the genera Succinea, Bulinus, Achatina, Clausilia, Pupa, Partula, Helix, Vitrina, Testacella, Limacella, Limax. LIMAX. _Lam._ Limacinea, Lam. and Bl.--_Descr._ Internal irregular, sub-quadrate, scutiform, crystalline; apex rounded, indistinct; epidermis, light brown, thin, extending beyond the margin.--_Obs._ The shell is placed under the scutellum of the common garden slug. Fig. 25, L. Antiquorum. LIMNACEA. Bl. The first family of the order Pulmobranchiata, Bl. The shells of this family are described as thin, with the outer lip always sharp. It contains the genera Limnea, Physa, Planorbis. LIMNEANA. Lam. A family of the order Trachelipoda, Lam. containing the following genera:-- 1. LIMNÆA. Spire produced; including _Physa_. Fig. 308 to 310. 2. PLANORBIS. Spire orbicular; including _Planaria_. Fig. 311, 312.