''Fenimorea janetae'', common name Janet's turrid, 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

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 in the family

Drilliidae The Drilliidae are a Taxonomy (biology), taxonomic family (biology), family of small predatory sea snails with high-spired shells. They are classified as marine (ocean), marine gastropod mollusks in the superfamily Conoidea. This family has no s ...

Description

The length of an adult shell varies between 25 mm and 40 mm; its diameter 14.3 mm. (Original description) The shell is rather large, with the posterior groove and an area about as wide as this groove, anterior to the groove, on the axial ribs, white. This is followed by a broad zone of chestnut-brown occupying about half the

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 between the summit and suture. This zone terminates a little below the periphery. Anterior to this is a fainter thread of brown and a little paler brown area in the groove just posterior to the fasciole. In addition to this, there are, in the lighter bands in the intercostal spaces, indications of pale brown markings. The broad brown band becomes enfeebled on the last portion of 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 ...

. The interior of the aperture is bluish white with the dark band shining partly through this, and the callus on the columellar area is porcelaneous. 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 ...

contains 1.5 small whorls, well rounded and smooth. The postnuclear whorls are appressed at the summit with a depressed groove occupying the posterior third between the summit and suture, evenly rounded from the anterior termination of this to the periphery, and marked by strong, broad, rounded, axial ribs. These have their strongest development anterior to the sinus at the summit and become attenuated posteriorly in crossing the base, where they extend to the basal fasciole. Of these ribs, 10 are present on the first four whorls, 12 on the fifth to seventh, 14 on the eighth and ninth, and 16 on the tenth. The spaces separating the axial ribs are about as wide as the ribs. In addition to this sculpture the whorls are marked by slender spiral threads in the depressed area near the summit, of which II are present on the body whorl. Anterior to the depressed area the threads are replaced by pitted impressed lines, which also cover the base. Between the threads and lines, under high magnification, still finer, closely spaced, microscopic spiral striations are present, and the ribs and the intercostal spaces also bear fine incremental lines with microscopic axial incised lines between them. The heavier incremental lines terminating anteriorly in the spiral line of pits divide the space between the spiral lines into scalelike elements suggesting the scales of some butterfly wings, each scale being bordered by a deeper axial depression and marked by microscopic axial striations, as well as the microscopic spiral lines, the axial striations being a little stronger. The columella has a moderately strong basal fasciole, which is bordered posteriorly by three feeble spiral threads and crossed by two more, whereas anterior to the basal fasciole the columella bears aboutsix feebly impressed spiral threads. The aperture is moderately large, rather broad, slightly channeled anteriorly with the posterior channel deeply incised and its wall reflected as a strong callus over the parietal wall. The stromboid notch at the anterior end of the outer lip is rather short and shallow. The space between the stromboid notch and the basal channel is clawlike. The parietal wall is covered by a moderately thick callus. There is a stronger

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 ...

about a quarter of a turn behind the aperture on the body whorl.Bartsch, P. (1934) Reports on the collections obtained by the first Johnson-Smithsonian deep-sea expedition to the Puerto Rican deep; new mollusks of the family Turritidae. Smithsonian Miscellaneous Collections, 91, 1–29, 8 pls
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Distribution

This species occurs in the

benthic zone The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning " ...

of the Caribbean Sea, the Gulf of Mexico and Puerto Rico; in the Atlantic Ocean between Florida and Brazil.

References

Rosenberg, G., F. Moretzsohn, and E. F. García. 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

Tucker, J.K. 2004 ''Catalog of recent and fossil turrids (Mollusca: Gastropoda)''. Zootaxa 682:1–1295

Fallon P.J. (2016). Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species. Zootaxa. 4090(1): 1–363

External links

* {{DEFAULTSORT:Fenimorea Janetae janetae Gastropods described in 1934