''Inodrillia amblytera'' 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 ...

Horaiclavidae Horaiclavidae is a family of predatory sea snails, marine gastropod mollusks in the superfamily Conoidea. In 2011 this family was split off from the family Pseudomelatomidae (formerly the subfamily Crassispirinae McLean, 1971) by Bouchet P., Ka ...

. It was previously included within the family

Turridae Turridae is a taxonomic family name for a number of predatory sea snails, marine gastropod mollusks in the superfamily Conoidea. MolluscaBase (2018). Turridae H. Adams & A. Adams, 1853 (1838). Accessed through: World Register of Marine Specie ...

, the turrids.

Description

The length of the shell attains 15 mm, its diameter 6 mm. (Original description) The shell consists of eight

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, rather thick, of a light yellow color, sometimes banded with reddish brown. The posterior sinus is nearly round, situated just below the suture, and has, in the best developed specimen, a thin, sharp edge rising a little above the surface of the shell, bending decidedly backward, then curving and nearly meeting in front. The outer lip rounds gradually to near the anterior end of 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 ...

, where it is slightly contracted, making a short, broad

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 ...

, then twisting abruptly backward produces a decided notch before joining the columella. A conspicuous

varix A varix (pl. varices) is an abnormally dilated vessel with a tortuous course. Varices usually occur in the venous system, but may also occur in arterial or lymphatic vessels. Examples of varices include: * Varicose veins, large tortuous veins usua ...

is formed by the thickening of the last rib, beyond which the outer lip is thin, white, and sharp-edged. There is a prominent, tooth-like projection on the interior of the aperture, at the end of the varix, more conspicuous in some specimens than in others, and seen best in an end view. The interior of the aperture and the inner lip is white. The columella is straight, with a conspicuous layer of enamel having a thin, free edge. The suture is distinct, undulating. The subsutural band is very narrow, concave, lapping well on the preceding whorl. Prominent, strong, oblique, rounded ribs, nine 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 ...

, separated by concave spaces of about the same width, cross the whorls from suture to suture, faintly defined on the subsutural band, and most prominent just below it. On the body whorl, these gradually lade away at the base of the siphon, and appear on the siphonal canal as conspicuous, much curved lines of growth. Microscopic striae intersect the fine lines of growth, giving to the entire surface of the shell a peculiar crinkled appearance. 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 broad, blunt, smooth, somewhat shining, consisting of two and a half whorls. The apical whorl is large, rising very little above the succeeding one. Bush, K.J. (1893) Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Gulf of Mexico (1877–1878), and in the Caribbean Sea (1879–80), and along the Atlantic Coast of the United States (1880), by the U. S. Coast Survey Steamer “Blake”, Lieut. Commander C. D. Sigsbee, U. S. N., and Commander J. R. Bartlett, U. S. N., commanding. XXXIV. Report on the Mollusca dredged by the “Blake” in 1880, including descriptions of several new species. Bulletin of the Museum of Comparative Zoölogy, 23, 199–244
(described as ''Pleurotoma (Drillia) amblytera'')

Distribution

This marine species occurs off

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and So ...

and

South Carolina )''Animis opibusque parati'' ( for, , Latin, Prepared in mind and resources, links=no) , anthem = " Carolina";" South Carolina On My Mind" , Former = Province of South Carolina , seat = Columbia , LargestCity = Charleston , LargestMetro = ...

, USA, at depths between 137 and 260 m

References

* Abbott, R.T. (1974). ''American Seashells''. 2nd ed. Van Nostrand Reinhold: New York, NY (USA). 663 pp

External links

Tucker, J.K. 2004 ''Catalog of recent and fossil turrids (Mollusca: Gastropoda)''. Zootaxa 682:1–1295
{{DEFAULTSORT:Inodrillia Amblytera amblytera Gastropods described in 1893