''Clionella aglaophanes'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

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 Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Clavatulidae Clavatulidae is a taxonomic family of sea snails, marine gastropod mollusks in the superfamily Conoidea. The family is not well differentiated morphologically. Clavatulidae was raised, based on cladistic analysis, from subfamily to the family ...

Description

The shell grows to a length of 7.6 mm. (Original description) The shell is high, narrow, conically cylindrical, with a blunt, flatly rounded apex, a short conical base, and scarcely any snout. It is hardly angulated, ribbed, contracted in the sinus area, but barely so at the suture. Its colour is grey, with a silvery sheen. The longitudinal

sculpture Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable sc ...

shows the whorls crossed from suture to suture by low, sharpish, subangulately projecting, dextrally convex, hardly oblique ribs, which run continuously, but are slightly diminishing in number, up the spire, there being about 15 on the last and 11 on the first regular

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 ...

. On the base they bend strongly to the right, and die out at the point of the snout. They are parted by hollowed furrows which are rather broader than they. Both ribs and furrows are scratched with very fine, almost microscopic lines of growth, which coincide with the course of the ribs. In the furrows a few of these lines are slightly stronger than the rest. The spiral sculpture shows below the sinus-area a very slight angular projection of the whorls, which is made more marked by a thickening and elevation of the ribs at this point. This is a feature which on the earlier whorls is very distinct, the whole rib being individualised by the central nodule into which it rises. But further on these nodules lose in importance. At the top of each whorl and close to the suture lies a small flattened thread, rising into minute longitudinal nodules at the ribs. Below this and above the angulation is a slight furrow where the scars of the old sinuses occur. In all this part the surface of the shell is covered by minute spiral threads which lower down become stronger. They are parted by minute furrows of about the same breadth as the threads. These are all exquisitely fretted by the longitudinal scratches. The colour of the shell is greyish, polished, with a very beautiful silvery sheen on the whole surface. The

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spires are ...

is conically cylindrical. The

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 ...

is small and the apex broad in proportion to the size of the shell. The profile-lines are hardly interrupted by the sutures. The apex consists of 1¼ broad, depressed, and flatly rounded, smooth whorls. The eight whorls increase very slowly. They are short, the last very small, being scarcely at all more tumid than the rest, and having a short conical base. The snout is very short. There is a small constriction round the top of each whorl. The profile-lines are faintly angulated, but are very slightly convex. The fine suture is well marked, being a little impressed and defined by the slight swelling round the top of the inferior whorl. The superior whorl scarcely contracts towards it. The

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...

is pear-shaped, with a slight angulation at the top and a very short

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. The outer lip is evidently thickened, but chipped in the only specimen present. It runs with an almost continuous slightly convex curve from the body to the siphonal canal, where the curve is slightly and shortly flattened. The sinus is very shallow and open. The inner lip is thickened and raised on a small but defined callus. It runs straight across the body to the base of the short, thick columella, down which it proceeds direct and parallel to the slightly prominent callus-edge on the left. The point of the columella is rounded and blunt, and hardly advances to the end of the snout, the canal-edge being thick and rounded, cut off obliquely upwards, but not at all reverted. This is an extremely peculiar little shell, remarkable in its narrow cylindrical and compact form, its sculpture, and its slight silvery sheen, from which last feature its name is derived.Challenger Expedition, Report on the scientific results of the voyage of H.M.S. Challenger; Zoology v. 15 pt. 41-43, 1886
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Distribution

This marine species occurs off

Puerto Rico Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and Unincorporated ...

, St Thomas and the

Virgin Islands The Virgin Islands ( es, Islas Vírgenes) are an archipelago in the Caribbean Sea. They are geologically and biogeographically the easternmost part of the Greater Antilles, the northern islands belonging to the Puerto Rico Trench and St. Croix ...

References

External links

* {{DEFAULTSORT:Clionella Aglaophanes aglaophanes Gastropods described in 1882