Description
(Original description Jos. C. Verco) The height of the shell attains 12 mm. The thin shell has a conical shape. The spire consists of nine whorls, including two smooth apical turns. The whorls are straight-sloping, with crowded spiral lirae, about 24 on the penultimate. They are crossed by oblique crowded accremental striae, producing sublenticular pitting. The suture is linear, immediately beneath the prominent peripheral cord which gradates the spire. The body whorl contains a suture that is slightly descending at the aperture. It has about 24 spiral threadlets. It is crowded with fine sinuous oblique accremental striae. The periphery is acutely angular, with a projecting rounded carina, spirally closely engraved on its upper surface andaxially crossed by rounded striae. These are much more distant than the accremental striae, provided at somewhat irregular intervals with 16 rounded invalid tubercles. The base of the shell is very flatly rounded with 7 concentric narrow lirae, the inner 4 closer than the rest, which are separated by 4 to 6 interlirate striae. The umbilicus is narrow, minutely axially incised. The aperture is oblique and roundly quadrate. The outer lip is slightly convex, thin, and smooth within The margin is sinuously convex below the suture, and concave towards the periphery. The basal lip is convex, slightly effuse, and smooth within. The upper third of the columella is concave, the rest is straight, and obliquely truncate below. The callus at the base partly borders the umbilicus and is attached to the columella along a vertical groove.
A spire is a part of the coiled shell of molluscs. The spire consists of all of the whorls except for the body whorl. Each spire whorl represents a rotation of 360°. A spire is part of the shell of a snail, a gastropod mollusc, a gastropod shell, and also the whorls of the shell in ammonites, which are fossil shelled cephalopods.
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the ammonites.
In anatomy, a suture is a fairly rigid joint between two or more hard elements of an organism, with or without significant overlap of the elements.
The shell is purple-brown, with somewhat oblique, axial, creamy, rhomboidal flames, extending from suture to suture, and nearly equalling the foundation colour in area. On the peripheral carina, and hence above the sutures, they are replaced by two or three creamy spots, while two or three less marked white spots occupy the intervals, and thus pick out the tubercles of the carina. Every whorl is encircled by four articulated colour bands, which in the white areas are of a more opaque white than the rest of these areas, and extend slightly beyond them, and are crossed by narrow vertical or oblique red lines, while in the purple areas they are of a deeper purple tint, and are crossed by narrow axial white lines. The base is of a lighter tint, the outer 6 cinguli of a rose pink, minutely dotted with creamy white. The columella and umbilicus are white, bordered outside with green, which tints the inner two basal cinguli, and curls around the columella into the throat. The inner edge of the outer lip is golden-brown and white, interior shining and nacreous.
The operculum is horny multispiral with a central nucleus. Aradial cellular fringe-like film extends over the inner three-fourths of each spiral.
The operculum, meaning little lid, is a corneous or calcareous anatomical structure like a trapdoor which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a minority of terrestrial gastropods, including the families Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc.
The formula of the radula is ~ .1.5. 1.5.1. ~. The central rachidian is heart-shaped, narrow free end surmounted by small, slightly serrated denticle. The other rachidians have trilobed cusps, which gradually enlarge outwards.There is a single lateral with one cusp trilobed at its base. The many marginals are unicuspidate, and not serrated. [2]
The radula is an anatomical structure that is used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the oesophagus. The radula is unique to the molluscs, and is found in every class of mollusc except the bivalves, who use instead cilia, waving filaments that bring minute organisms to the mouth.
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