''Fenimorea marmarina'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

, a marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Drilliidae.Bouchet, P. (2016). Fenimorea marmarina (Watson, 1881). In: MolluscaBase (2015). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=872005 on 2016-04-14

Description

The shell grows to a length of 17 mm. (Original description) Shell.—Biconical, with a high pointed

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. Spire ...

, a short lopsided base, and a very short snout, ribbed, barely tubercled, with spiral furrows, and a compressed band below the scarcely impressed suture. Sculpture. Longitudinals—there are on the

body whorl The body whorl is part of the morphology (biology), morphology of the gastropod shell, 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 ...

15 rather narrow, spread-out, rounded, scarcely oblique direct ribs. These begin at the upper suture and extend to the base, but not to the snout. Near the top they are cut by a spiral furrow, so that the upper part of them forms a series of small rounded tubercles just below the suture. Below the spiral furrow the ribs are slightly swollen into knots. The ribs are parted by wider shallow furrows: these ribs and furrows run pretty regularly down the spire, but there are fewer of them on the earlier

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). In nature File:Photograph and axial plane floral diagra ...

s. The whole surface is further scored by almost microscopic regular hair-like lines of growth, which are specially sharp whorls, which constricts both the ribs and the interstices. On the body whorl there are 18 or 20 shallow and narrow furrows parted by flat interstices of about three times their width. These do not extend to the sinus-area, and only very doubtfully to the snout, where there are rather a few irregular and scarcely raised rounded threads. These furrows are not recognizable on the earlier whorls. The whole surface is very delicately fretted with almost microscopic, crisp spiral striae whose course is not quite regular, and which are crimped or disturbed by the lines of growth. This sculpture is particularly sharp and distinct in the sinus-area. The colour of the shell is pure marble-white. The spire is very regularly conical. There are about two embryonic whorls on 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 " ...

, which are small, nearly cylindrical, with scarcely appreciable suture, and end in a blunt, round, laterally flattened-down tip. The shell contains 10 whorls in all, rather short and broad, scarcely at all convex. The body whorl is large, being broad and tumid, but not long, with a tumidly conical lop-sided base, ending in a short, broad, flat snout which is abruptly and straight cut off. The suture islinear, but well defined by the swelling of the infrasutural row of tubercles. The

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

is oval, with an acute angle above, an obtuse angle at the side where the body and the

columella Lucius Junius Moderatus Columella (, Arabic: ) was a prominent Roman writer on agriculture in the Roman Empire. His in twelve volumes has been completely preserved and forms an important source on Roman agriculture and ancient Roman cuisin ...

join, and a truncation at the point. The outer

lip The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...

is thin, a little patulous, with an equable convex curve throughout. The anal sinus is very shallow and round, with no shelf above it; and below it is a very high but little prominent shoulder made by the very slightly advancing lip-edge. The inner lip is very narrow, shallowly hollowed into the substance of the shell. The columella is straight, conical, and is obliquely cut off in front with a blunt, rounded, scarcely twisted edge. R.B. Watson, Mollusca of H.M.S. ‘Challenger’ Expedition.—Part X; Journal of the Linnean Society of London, Zoology Volume 15, Issue 88, pp. 457–475, November 1881
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Distribution

This species occurs in the

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

off

Northeast Brazil The Northeast Region of Brazil ( ) is one of the five official and political regions of Brazil, regions of the country according to the Brazilian Institute of Geography and Statistics. Of Brazil's twenty-six states, it comprises nine: Maranhão, ...

References

External links

* {{DEFAULTSORT:Fenimorea Marmarina marmarina Gastropods described in 1881