''Inodrillia pharcida'' 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 ...

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

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 ...

Horaiclavidae. It was within

Turridae Turridae is a Taxonomy (biology), taxonomic family (biology), family name for a number of predatory sea snails, Marine (ocean), marine gastropod mollusks in the superfamily Conoidea.MolluscaBase (2018). Turridae H. Adams & A. Adams, 1853 (1838). ...

Description

The length of the shell attains 9.5 mm, its diameter 3.5 mm. (Original description) The slender, thin shell is yellowish-white, with a dull surface, except for the glassy and translucent

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 " ...

. It contains 8

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 protoconch is thin, inflated, the (nuclear) first two whorls) polished, smooth, and free from

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 ...

, passing abruptly into the dull and lustreless surface of the adult shell. For the remainder, the transverse sculpture consists of subequal rils, largest on the periphery, smaller toward the sutures, which they reach above and below, the track of the notch not being marked by a flattened band, as is generally the case. There are about eleven of these to a whorl, 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 ...

they are less pronounced, and become obsolete toward the anterior third of the whorl, where the lines of growth are particularly conspicuous. The completion of the adult

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 marked by a particularly large rib or swelling of the margin, which becomes more conspicuous in case the shell continues to grow. In the older part of the shell the ribs are continued in the same line from whorl to whorl, in the body whorl and a half they become alternate or irregular. The revolving sculpture consists of (on the smaller whorls) two or three to (on the body whorl) sixteen flattened raised bands, with wider interspaces, which are much more marked, or even knobby, on the smaller whorls where they pass over the transverse ribs, gradually become more uniform, and, on the last whorl, are nearly as well defined between the ribs as on them. Nine of those on the body whorl are crowded together on the anterior third, the rest spread over the body of the whorl. There are hardly any traces of revolving striation. The notch is deep, but not producing a band. The margin of the

is thin. 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 produced forward, a slight deposit on 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 ...

. The columella is nearly straight, slightly shorter than the rather wide, somewhat recurved

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 i ...

. The sutures are appressed, sinuous over the ends of the transverse ribs. The aperture measures less than one third of the shell.Dall, W. H. 1881. Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Gulf of Mexico, and in the Caribbean Sea, 1877-79, by the United States Coast Survey Steamer 'Blake,'. Bulletin of the Museum of Comparative Zoology 9: 33–144
(described as ''Pleurotoma {Drillia) exasperata'')

Distribution

This marine species occurs in the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

and

Barbados Barbados, officially the Republic of Barbados, is an island country in the Atlantic Ocean. It is part of the Lesser Antilles of the West Indies and the easternmost island of the Caribbean region. It lies on the boundary of the South American ...

References

Dall, W. H. 1889b. Reports on the results of dredgings, under the supervision of Alexander Agassiz, in the Gulf of Mexico (1877–78) and in the Caribbean Sea (1879–80), by the U. S. Coast Survey Steamer 'Blake,' Bulletin of the Museum of Comparative Zoology 18 1-492, pls. 10–40

External links

Rosenberg G., Moretzsohn F. & García E. F. (2009). ''Gastropoda (Mollusca) of the Gulf of Mexico'', Pp. 579–699 in Felder, D.L. and D.K. Camp (eds.), Gulf of Mexico–Origins, Waters, and Biota. Biodiversity. Texas A&M Press, College Station, Texas
{{DEFAULTSORT:Inodrillia Pharcida pharcida Gastropods described in 1889