Derived its name from the long, conical-pointed, somewhat recurved tooth
in the outer lip, by which alone it can well be distinguished from the
Purpura; and with this characteristic difference the description of the
shell of the Purpura will answer for this genus.
Monoceros cingulatum.
M. imbricatum.
M. striatum.
M. glabratum.
M. crassilabrum.
_M. cingulatum._ The belted Monoceras.
Cylindrical, columella not smooth, but irregularly plaited or wrinkled,
and the tooth does not extend within the interior of the whorls as in
the other species, but appears affixed only to the edge of the lip;
volutions flattened in their upper edges; transverse spiral brown bands.