8 INTRODUCTIO. 
outer lip with the margin acute, posteriorly sinuated, inter- 
nal with an elevated, transverse ridge. 
ll. Genus Marinula King. F oot simple inferiorly, with- 
out a transverse groove. — Shell ovate-oblong, imperforate, 
solid, smooth ; spire short, acute; aperture oboalle: inner hp 
litoads excavated, with three plaits, the posterior the largest ; 
outer lp posteriorly sinuated, internally simple, the margin 
acute. 
Sub-gen. Monica H. et A. Adams.  (Turcia in textu 
p. 247.) Shell oblong-conical; spire elevated, whorls trans- 
versely striated; outer lip thickened internally, and furnished 
with three plait-like teeth. 
12. Genus Lewconia Gray. Foot divided inferiorly by 
a transverse groove. — Shell ovate-oblong, imperforate, smooth; 
spire conical; aperture elongate, oval; inner lip with two plaits 
anteriorly; outer lip smooth internally, the margin simple, 
acute. 
13. Genus Pedipes Adanson. Foot divided inferiorly by 
a transverse groove. — Shell sub-globose, imperforate, trans- 
versely striated; spire short, obtuse; aperture narrow; inner 
lip flattened, exeavated, with three plaits, the posterior the 
largest; outer lip posteriorly sinuated, with two teeth inter- 
nally; margin acute. 
IIl. Sub-fam. Otininae. Animal amphibious, living 
near the sea.  Tentacles rudimentary; eyes placed on the 
head. — Shell ear-shaped; columellar margin simple; outer 
lip simple, acute. 
14. Genus Otina Gray. Tentacles nearly obsolete; eyes 
sessile on the upper part of the head at their hind bases. 
Foot divided by à transverse groove across its centre, and 
furnished with a creeping disk at each end. — Shell ovate, 
of few whorls, the first very large and ventricose, those of 
the spire very small; aperture large, oblong, entire; inner lip 
without plaits; outer hp simple, acute. 
Genera, ut vidimus, varia ab Auctoribus ad familiam 
nostram relata sunt nunc animalium et testarum cognitione 
exactiore ex ea rejicienda. Melanopsis et Melania (L a m.) duce 
Cl. Philippi ad Paludinacea, Lémnaea (Lam.) ad Limnae- 
acea, Pyramidella (F ér.) ad Pyramidellacea, Tornatella (F ér.) 
ad Dullacea, Physa, Planorbis et Ancylus (Latreille) ad 
Limnaeacea, Acme (Deck) ad Aciculacea, Chilina (Gray) ad 
Limnaeacea, Tornatellina (K üster) ad Helicea, Conulus et Ja- 
minia (Küst.) ad Pyramidellacea transferantur. 
