A beautiful and numerous genus of turreted shells, with an expanded
outer lip and short beak; the greater part are marine; many are found at
the mouths of rivers, and a few in lakes, though none can properly be
called river shells. In appearance they are like an elongated pyramidal
cone, and the spire is at least two thirds the length of the shell. The
exterior is seldom smooth, but striated, tuberculated, granulated, or
spinous.
Shell more or less turreted, generally tuberculated; aperture small,
oval, oblique; the columellar edge hollowed, callous; the right edge
sharp, and dilating a little with age; operculum horny, oval, rounded,
sub-spiral, and striated.
Cerithium giganteum.
C. palustre.
C. sulcatum.
C. telescopium.
C. ebeninum.
C. erythræonense.
C. muricatum.
C. radula.
C. crassum.
C. decollatum.
C. nodulosum.
C. vulgatum.
C. obeliscus.
C. granulatum.
C. aluco.
C. echinatum.
C. subulatum.
C. heteroclites.
C. zonale.
C. semiferrugineum.
C. torulosum.
C. tuberculatum.
C. morus.
C. obtusum.
C. semigranosum.
C. asperum.
C. lineatum.
C. vertagus.
C. fasciatum.
C. ocellatum.
C. literatum.
C. atratum.
C. eburneum.
C. punctatum.
C. lima.
C. perversum.
_C. vertagus._ The curved beak Cerithium. Pl. 24, fig. 3.
Species with evidently a small canal, very short, and recurved obliquely
towards the back.
_C. aluco._ The caterpillar Cerithium.
Species with a canal much smaller, but entirely straight, and a sinus
well formed at the posterior union of the two edges.
_C. semigranosum._ The semi-granulated Cerithium.
Fusiform, turreted; apex acute; the suture with double spiral rows of
large granules; minutely striated transversely, with sulcated
granulations; colour reddish brown.