300 MANUAL OF THE MOLLUSCA. 
beneath the mantle; foot oval, much smaller than the mantle; 
length 34 inches. Coast of Chili. (Requires confirmation.) 
VAGINULUS, Férussac. 
Type, VY. Taunaisu, Férussac. 
Synonym, Veronicella, Bl. 
Animal elongated, slug-like, entirely covered by a thick 
coriaceous mantle, smooth or granulated; head retractile under 
mantle; tentacles 4, upper pair slender, cylindrical, inflated at 
the tips and bearing eyes, lower pair short, bifid; foot linear, 
pointed behind; sexes united; ¢ orifice behind the right ten- 
tacle, 9 midway on the right side, beneath the mantle; 
respiratory and excretory orifices at posterior extremity between 
mantle and foot. Inhabits forests, in decayed wood and under 
leaves. 
Distribution, 20 species. "West Indies, South America, India, 
Philippines. 
FAamMiIty L[V.—LIMN2IDZ. 
Shell thin, horn-coloured; capable of containing the whole 
animal when retracted ; aperture simple, lip sharp; apex some- 
times eroded. 
Animal with a short dilated muzzle; tentacles 2, eyes sessile 
at their inner bases; mouth armed with an upper mandible, 
tongue with teeth similar to Helix. The Limneeids inhabit 
fresh waters in all parts of the world; they feed chiefly on 
decaying leaves, and deposit their spawn in the form of oblong 
transparent masses on aquatic plants and stones. They fre- 
quently glide beneath the surface of the water, shell downwards, 
and hybernate or estivate in the mud. 
The fresh-water snails (and also Neritina) can lower them- 
selyes from aquatic plants by a mucous thread, and re-ascend 
by the same ; a Physacan be lifted out of the water by its thread. 
LimNnZA,* Lamarck. Pond-snail. 
Etymology, Limnaios, marshy. 
Type, L. stagnalis, Fig. 128. Pl. XIL., Fig. 30. 
Shell spiral, more or less elongated, thin, translucent; body- 
whorl large, aperture rounded in front; columella obliquely 
twisted. 
Animal with a short, broad head; tentacles triangular, com- 
pressed; lingual teeth (LZ. stagnalis) 55.1.55, about 110 rows, 
entral teeth minute, laterals bicuspid, the inner cusp largest, 
* Adjectives employed as names for shells shor’ 4 have the feminine termiaticn. 
