It is a singular marine shell, often found in great numbers floating on the surface of the sea, suspended by a vesicular appendage, which stains the hand of a purple colour.
Shell sub-globular, ventricose, extremely thin and fragile; transparent, of a beautiful violet colour; the spire low, lateral, pointed, with sub-carinated whorls; aperture large, sub-angular, greatly modified by the last whorl of the spire; edges disunited, the left entirely formed by the columella, which is straight and continued beyond the base, the right edge sharp, often with a sinus in the middle.
Janthina communis.
Janthina exigua.
J. communis. The common Janthina. Pl. [18], fig. 6.
Very fragile, aperture triangular, with a small notch on the margin of the outer lip; beautiful violet colour.
FAMILY XII.
Macrostomides. Four genera.
1. Sigaretus. Four species.
Distinguished from the Natica by the great width of the aperture, and its short spiral columella.
Shell oval, more or less thick, very depressed, spiral short, little elevated, lateral; aperture very extended, entire, the left edge reflected and sharp; two lateral muscular impressions very disunited.