Species in which the tube is rather long, and the notch is a little posterior to the middle of the edge.
P. auriculifera. The eared Pleurotoma.
Species in which the tube is short, and the notch entirely against the spire.
P. nodifera. The knotty or Javanese Pleurotoma.
Species with outer lip largely notched and deeply crenulated; upper volution smooth; under volution and body striated transversely, with angulated oblique nodules at the suture; colour reddish yellow.
3. Turbinella. Twenty-three species.
By Linnæus this genus was classed with the Voluta, though they are more closely allied to the Murex; differing, however, from them by having no varices.
Shell generally turbinated, but sometimes turreted, rugged, and thick; spire variable in form; aperture elongated, terminated by a straight canal, often rather short; the left edge almost straight, and formed by a callosity which hides the columella; the right edge entire and sharp; the columella with two or three unequal, almost transverse plaits.
Turbinella scolymus.
T. rapa.