LINGULA. 57 
LIMACINA. Cuv. (Limaz, a snail.) Fam. Pteropoda, Lam. 
Deser. «Papyraceous, fragile, planorbicular, sub-carinated, 
obliquely convolute ; spiral side rather prominent, the other side 
umbilicated, aperture large, entire, not modified, peristome 
sharp. Obs. This isSprratretua, Bl. The shell figured as Lima- 
cina in Sowerby’s Genera, Art. Pteropoda is an Adlanta. 
Spiratella Limacinea, fig. 224, copied from Blainville. 
LIMACINEA. Bl. The third family of the order Pulmobran- 
chiata, including the genera Succinea, Bulinus, Achatina, 
Clausilia, Pupa, Tomogerus, Helix, Vitrina, Testacella, Parma- 
cella, and Limax. 
LIYMAX. Fam. Limacinea, Lam. and Bl. Descr. Internal, irre- 
gular, sub-quadrate, scutiform, crystalline; apex rounded, indis- 
tinct ; epidermis light brown, thin, extending beyond the margin. 
Obs. The shell is placed under the scutellum of the common 
garden slug. Fig. 259, L. Antiquorum. 
LIMNACEA. BI. The first family of the order Pulmobranchiata, 
Bl. containing the genera Lymnea, Plysa and Planorbis. 
LIMNEA. Lam. (Awvas limnas, lacustrine.) Fam. Limnacea, 
Lam. and Bl. Descr. 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; colum- 
ella 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, (Succinea,) in shape, but the 
animal of the latter is amphibious, and the shell is of a bright 
amber colour. L. Stagnalis, fig. 308. L. Aserta, fig. 309. (Rapix 
Montf.) The reverse species have been separated under the 
name Physa, 310. Other generic names have been given to 
other species. 
LINES OF GROWTH. The concentric striz or lines, formed 
by the edges of the successive layers of shelly matter deposited 
by the animal, by which it increases the shell. The outer edge 
of the aperture is always the last line of growth. 
LIN’GUIFORM. (Lingua, tongue; forma, form.) Tongue-shaped. 
LIN’GULA. (Dim. from lingua, tongue.) Fam. Brachiopoda, Lam. 
Palliobranchiata, Bl. Descr. Equivalve, oblong, depressed, thin, 
equilateral, gaping and pointed at the umbones, gaping and trun- 
cate or trilobate at the opposite extremities, attached by a fleshy 
pedicle fixed to the umbones. Obs. This is the only bivalve shell 
which is pedunculated, in which respect it constitutes a singular 
anomaly. The ancient writers, from seeing the separate valves, 
placed it in their systems under the name Patella Unguis. There 
are several recent species found in the Molluccas, and some fossils 
in sandy indurated marl, in Durham limestone and in alluvium 
of Suffolk. L. Anatina, fig. 219, is so named from its resemblance 
to a duck’s bill. I 
