GASTEROPODA. LIMACIDZ. 45 
tected by a shell of the same form; whilst in Ancylide they 
are conical, and are covered by a conic shell. 
The two first families, Limacidze and Helicide, have four 
tentacula ; the upper ones of which bear eyes at their extremi- 
ties. All the other families have but two tentacula, which are 
furnished with eyes at their bases. 
The sexes are hermaphrodite. The impregnation is mutual 
in Limiacidee, Helicidee and Carychiade ; whilst in Limnade, 
if there be but two individuals, one only is impregnated. 
FAMILY I. LIMACID. 
Corpus oblongum sepius nudum. Pes abdominalis. Caput 
tentaculis quatuor ; superioribus elongatis, ad apicem oculi- 
geris ; inferioribus brevissimis. 
STIRPS I. 
Corpus nudum anticé supra disco thoracico cor, branchiasque 
tegente, instructum. Sexus hermaphroditus. Apertura late- 
ralis dextra, thoracica. 
Synopsis Generum. 
Apertura lateralis ante medium disci. Dorsum 
non carinatum, at Glanduld gaa termi- 
nali instructum....... 2 heute emg Os. A RIOR. 
Apertura lateralis sate gins fee “Worst 
posticé saltem carinatum, nig Glanduld 
LENE ee ees Re pe we penal) 36 Vil Sa 
Body of the Limacide ameeTs naked, foot abdominal, head 
with four tentacula; the upper ones elongated, bearing the 
eyes at their extremities ; under ones very ore. 
Those of the first stirps have their body naked, the anterior 
and upper part being furnished with a thoracic disc, covering 
the heart and respiratory organs. The sexes hermaphrodite. 
The lateral aperture on the right side of the thorax. 
The animals of this family are indiscriminately named Slugs. 
The mouths of these animals are furnished with a horny con- 
