Janthina globosa
Swainson, 1822
Description:
Dimensions range from 12 mm - 38.5 mm high and 10 mm wide.
Width to height ratio: 0.83:1 ~ 0.26:1
Shell: globose; lightweight; small to moderately small. Exterior colour reddish to dark violet or purple, with diffuse, narrow pale violet band below suture, base or upper whorls sometimes a bit darker. About 4 whorls, rounded, often slightly shouldered . Suture narrowly canalised. Umbilicate: closed, or very narrow, partially covered by a thin columellar callus. Intercostal spaces sculptured by weak, irregular V-shaped growth lines. Base slightly convex with a few weak spiral lines. Columella slightly bent, smooth. Aperture oval, longer than broad,more than half of shell length, extended anteriorly in some specimens; outer lip thin, indented in the centre.
Distribution:
World-wide, in tropical and temperate seas; Cocos Keeling Islands [Maes, 1967:117]; available Australian specimens range from southern Queensland southwards to Bermagui, NSW [Beechey, 2008]; Northern Territoory, Qld, NSW, Tasmania, New Zealand, Hokkaido to Honshu Japan [Beu, 2017: 184]; entire Gulf of Mexico, North Carolina to Brazil [Rosenberg et al., 2009:643]
Habitat:
Pelagic, found washed up on beaches
Etymology:
from globosus [latin] = spherical or globular
Type Material:
none mentioned in source material for Janthina globosa Swainson, 1822. []

Swainson, W. (1822). Plate 85. Fig. 2.
Distribution
as listed in source literature
Blainville, H. M. D. de (1822).
Shown in text as Janthina prolongata Blainville, 1822
Reeve, L. A. (1858).
Shown in text as Ianthina decollata P. P. Carpenter, 1857

Shell globose, with a short, slightly immersed spire; whorls impressed at the sutures, then rounded, finely decussately striated throughout; whitish, purplish-violet at the spire and base; columella slightly reflexed, pressed against the upper part, then prolonged; aperture somewhat broad, slightly sinuate in the middle, with a channel at the base.
Reeve, L. A. (1858).

Shell globose, thin, inflated, with a short, slightly immersed spire; whorls impressed at the sutures, then rounded, finely decussately striated throughout; whitish, purplish-violet at the spire and base; columella slightly reflexed, elongated; aperture broad, open, slightly sinuate in the middle, with a channel at the base.
Reeve, L. A. (1858).
Shown in text as Ianthina iricolor Reeve, 1858



















