Species in which the aperture is oblique; the columella losing itself entirely in its continuation with the margin, the umbilicus always uncovered; colour black and white.
T. setosus. The bristly Turbo.
Thick, transversely and deeply sulcated, longitudinally striated; spire short, volutions rounded, lip crenulated; inside pearly, variegated with white, green, and brown.
T. rugosus. The rough Turbo.
Species of which the aperture is perfectly round in the direction of the axis; the operculum horny.
5. Planaxis. Two species.
Shell marine, generally small, solid, of an oval conical form, oblong, a little sloping in front; columella flattened and truncated anteriorly; right margin furrowed or radiated within, and thickened by a callosity running to its origin; operculum oval, thin, horny, and sub-spiral.
Planaxis sulcata.
Planaxis undulata.
P. sulcata. The furrowed Planaxis. Pl. [27], fig. 4.