Species of gastropod
Bullia callosa, common name the callused bullia, is a species of sea snail, a marine gastropod mollusk in the family Nassariidae, the Nassa mud snails or dog whelks.[1]
Description
The length of the shell varies between 18 mm and 50 mm.
The shell is elongated and cylindrical. The whole external surface is smooth, shining, of a coffee and milk color. The elongated spire is pointed. It is composed of six not convex whorls. Each whorl is covered between the sutures with a layer of matter, which assumes at the base a chestnut color. This layer is much thicker upon the body whorl, and is continued, enlarging itself, to the left lip, where it forms a large semicircular callosity, of a deep chestnut color, bordered with white. Each of the whorls of the spire is likewise separated from the others by a fawn-colored line, which is delineated a little below each suture. The aperture is ovate, of a pale fawn-color, dilated towards the middle, strongly emarginated at its base. The columella is arcuated, callous, fawn-colored and smooth. The callosity of the columella is oblique, thick, furrowed, much shorter than the outer lip. From its lower part, a stria stretches out, which is directed obliquely upon the back of the shell, to its termination at the anterior angle of the right lip, which is sharp.[2]
Distribution
This marine species occurs from Angola to Mozambique.
References
- Marais J.P. & Kilburn R.N. (2010) Nassariidae. pp. 138–173, in: Marais A.P. & Seccombe A.D. (eds), Identification guide to the seashells of South Africa. Volume 1. Groenkloof: Centre for Molluscan Studies. 376 pp.
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