Kingdom Animalia Class Gastropoda Superfamily Trochoidea Rank Species | Phylum Mollusca Clade Vetigastropoda Family Trochidae | |
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Similar Gibbula spurca, Gibbula racketti, Gibbula fanulum, Gibbula spratti | ||
Gibbula tryoni is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.
Contents
Description
The size of the shell attains 17 mm. The umbilicate, rather thin shell has a conical shape. It is crimson or purplish red, obscurely, rather finely mottled with arrow-shaped whitish dots, usually with several narrow articulated lines on the base, and in the middle of the upper surface of the body whorl. The yellow, apical whorls are eroded. The spire is conic. The five whorls are a little tumid below each suture, and with a narrow ledge or margin, marked off by an impressed line, above each suture. This peripheral ledge gives the body whorl a rather prominent keel. The surface is polished, but shows quite prominent, spaced, impressed growth lines, and under a lens is all over very densely minutely spirally striate. The base of the shell is flattened, rather prominent around the umbilicus. The oblique aperture is quadrangular, smooth and with a very brilliantly iridescent green nacre inside. The columella is arcuate above and expanded partly over the umbilicus. The parietal wall is free from callus. The umbilicus is deep, with a narrow rapidly tapering perforation, but broad and funnel-shaped at the opening.
Distribution
This marine shell occurs off Port Elizabeth and Port Alfred to North KwaZuluNatal, South Africa