''Pleurotomella pudens'' is a species of

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a marine

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk in the family

Raphitomidae Raphitomidae is a family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Bouchet P. & Rocroi J.-P. (Ed.) (2005). "Classification and nomenclator of gastropod families". ''Malacologia'' 47(1-2). . 39 ...

Description

The length of the shell attains 5.3 mm, its diameter 2.5 mm. (Original description) The white shell is small, oblong, smooth, with a high, subscalar, small and sharp-pointed apex, a short and scarcely swollen

body whorl The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the b ...

, and a conical base produced into a broadish, triangular, lop-sided aperture. Sculpture. Longitudinals – besides hairlike lines of growth, there are some faint, very oblique, upwardly convex folds, which are obsolete on the earlier and on the last whorls. Spirals – the surface is covered with superficial rounded threads which, obsolete in the sinus-area, are feeble on the body, but sharper and more distinct on the base and aperture. There is a very faint angulation below the sinus-area. The colour of the thin shell is semi-transparent white, with hardly any gloss. The spire is conical, subscalar from the slight short tumidity below the suture. The

protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called ...

consists of 4 embryonic whorls, which are buff, darkening to orange at the tip. They are a little broadly conical, rounded, with a slight angulation, and parted by a distinct suture. They rise to a very minute, spirally scratched, round, and very slightly prominent knob. They are sculptured with raised bars, which are straight and simple above, but oblique and crossed below. The shell contains 7½

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ...

s in all. They are slightly concave and shouldered in the sinus-area, which is bordered by a faint angulation, below which they are slightly tumid, without any contraction into the inferior suture. The

, which is rather small, has a conical base produced into a broadish, triangular, one-sided aperture. The suture is slight, inasmuch as the inferior whorl laps up on the one above. But there is an appreciable constriction. The aperture is oblong and pointed above. There is no

siphonal canal The siphonal canal is an anatomical feature of the shells of certain groups of sea snails within the clade Neogastropoda. Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is ...

below except the channel behind the columella. The outer lip is very thin. Its curve is somewhat flattened. Its edge forms a very regular sweep with a rather high shoulder above, between which and the body lies the deepish, but broad, open-mouthed sinus. The inner lip is very thin and narrow, dying out early on the scarcely oblique or twisted edge of the longish, straight, and conical columella, the point of which comes short of the lip-edge, and whose junction with the body is concave.

Description

Distribution

References

External links