''Comitas anteridion'' 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 Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

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 ...

mollusc 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 esti ...

in the family

Pseudomelatomidae Pseudomelatomidae is a family of predatory sea snails, marine gastropods included in the superfamily Conoidea (previously Conacea) and part of the Neogastropoda ( Bouchet & Rocroi, 2005). In 1995 Kantor elevated the subfamily Pseudomelatomina ...

, the turrids and allies.MolluscaBase (2018). Comitas anteridion (Watson, 1881). Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=433329 on 2018-06-0

Description

The high, narrow shell has a biconically fusiform shape. it is subscalar, with angularly convex and longitudinally ribbed

whorls 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 d ...

. It is thin and tawny. Sculpture : Longitudinals—a little way below the suture is an angulation where narrow, raised, oblique ribs begin. These slope from right to left. They extend to the suture, but not to the base, where they die out more gradually than they arose. They are parted by rounded hollows, which are wider than the ribs. There are about nineteen of these ribs and hollows on 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 ...

, but fewer on each preceding one. Besides these, there are very many fine hair-like flexuous lines of growth. Spirals —the shoulder below the suture (the sinus area) has a few faint regular scratchlike lines; on the ribbed area these are stronger. On the base the interstices become somewhat narrower and more convex, till on the aperture they rise into strongish threads, which at the very point again become weaker. The colour of the shell is a light tawny, paler on the aperture, and white on the columella. The spire is high, conical, and slopingly subscalar. 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 ...

is broken. The shell contains probably 10 whorls, rather short, with a straight somewhat drooping shoulder, convex, and appearing contracted below in consequence of the dying out of the longitudinal ribs as they approach the suture. The conical base contracts rather rapidly, and is prolonged into the straight, very slightly reverted, direct, narrow, cylindrical aperture. The suture a fine, regular, squarely impressed line, whose course diverges a good deal from that of the spirals of sculpture. The aperture is club-shaped, being roundly oval and not angulated above, and with a long, narrow, slightly twisted

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 sharp and thin, with a very regular curve from the suture to the base of the aperture, along the edge of which it runs sharp and straight to the open, rounded, and thin point. When it leaves the body, it retires at once to the left, forming a deep, rounded, open sinus. From this point its edge sweeps out in a full convex curve, retreating slightly at the base of the aperture, and then advancing straight to the point. The inner lip is porcellanous, longitudinally marked, narrow, straight, cut away obliquely to a long fine point ; and then continued along the siphonal canal in a thin sharp edge, which toward the point is slightly cut off backwards. Report on the scientific results of the voyage of H.M.S. Challenger during the years 1873-76 under the command of Captain George S. Nares ... and the late Captain Frank Tourle Thomson, R.N.; Zoology vol. 15 (1886)

Distribution

This marine species occurs off

Cape of Good Hope The Cape of Good Hope ( af, Kaap die Goeie Hoop ) ;''Kaap'' in isolation: pt, Cabo da Boa Esperança is a rocky headland on the Atlantic coast of the Cape Peninsula in South Africa. A common misconception is that the Cape of Good Hope is t ...

, South Africa.

References

* R.B. Watson, 1886; Preliminary Report on the Scaphopoda and Gasteropoda collected by the H. M. S. Challenger during the years 1873–76; Journal of the Linnean Society of London vol. XV p. 399 * A.W.B. Powell, 1966, 969. The family Turridae in the Indo-Pacific. Pt. 2. The subfamily Turriculinae. IndoPacific Mollusca 2 (10): 207-414 * R.N. Kilburn, Turridae (Mollusca: Gastropoda) of southern Africa and Mozambique. Part 3. Subfamily Borsoniinae; Ann. Natal Mus. Vol. 27(2), December 1986

External links

* {{Taxonbar, from=Q3715709 anteridion Gastropods described in 1881