''Inodrillia amblytera'' 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 ...

Horaiclavidae. It was previously included within the family

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). ...

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

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 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 ...

rounds gradually to near the anterior end of 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 ...

, 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 i ...

, then twisting abruptly backward produces a decided notch before joining 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 ...

. A conspicuous varix 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 (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 ...

, 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 U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

and

South Carolina South Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders North Carolina to the north and northeast, the Atlantic Ocean to the southeast, and Georgia (U.S. state), Georg ...

USA The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous ...

, 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