''Compsodrillia eucosmia'' 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 ...

mollusc 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 esti ...

in the family

Pseudomelatomidae Pseudomelatomidae is a family of predatory sea snails, marine gastropods included in the superfamily Conoidea (previously Conacea) and part of the Neogastropoda ( Bouchet & Rocroi, 2005). In 1995 Kantor elevated the subfamily Pseudomelatomina ...

, the turrids and allies.

Description

The length of the shell varies between 10 mm and 25 mm. (Original description) The color of the shell is pale, with touches of pale brown and a peripheral whitish zone. 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). Whorls in nature File:Photograph and axial plane floral ...

s, with a glossy, rounded

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 ...

of two whorls. The

fasciole A fasciole in mollusks refers to a band or ribbon-like structure that is often seen as a flattened, slightly depressed area on the shell, formed by the successive growth lines on the edges of a canal. It is typically found on the surface of the she ...

is rather wide, excavated, undulating in harmony with the ribs, marked by fine revolving threads and marginated at the appressed suture by a stout elevated line. The spiral sculpture on the rest of the shell (1) consists of (on the whorls preceding 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 ...

) two or three prominent white stout threads, somewhat swollen where they ride over the ribs. On the body whorl there are about fifteen of these primary spirals. Between the fasciole and the end of the siphonal canal, in each of the wide interspaces, are (2) three or four much finer hardly elevated flattish threads, similar to those on the fasciole, and on the body whorl the marginating thread behind the fasciole is wider and somewhat crenulated. The transverse sculpture consists of (on the penultimate whorl 9) stout, rounded ribs, beginning at the fasciole and obsolete on the

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 ...

. Beside these there are only incremental lines. The brown touches are on these ribs above and below the white zone, which is bounded by the peripheral pair of primary spirals. The final varix is stout and rounded. The aperture is narrow. The notch is rounded and strongly marked. The outer lip is thin, arched forward and not lirate within. A single internal thread runs parallel with the fasciole deeper in the throat. The inner lip shows a thin callus with an elevated margin. The columella is straight. The siphonal canal is short, obliquely truncate and rather wide.

Distribution

''C. eucosmia'' can be found in the Gulf of Mexico, off the coast of

Suriname Suriname (; srn, Sranankondre or ), officially the Republic of Suriname ( nl, Republiek Suriname , srn, Ripolik fu Sranan), is a country on the northeastern Atlantic coast of South America. It is bordered by the Atlantic Ocean to the north ...

; also off

Grenada Grenada ( ; Grenadian Creole French: ) is an island country in the West Indies in the Caribbean Sea at the southern end of the Grenadines island chain. Grenada consists of the island of Grenada itself, two smaller islands, Carriacou and Pe ...

.Tunnell, John W., Jr., Felder, Darryl L., & Earle, Sylvia A., eds. ''Gulf of Mexico Origin, Waters, and Biota, Volume 1: Biodiversity.'' Texas A&M University Press, 2009. 669.

References

* Absalão, R. S.; Pimenta, A. D. & Caetano, C. H. S. 2007. Turridae (Mollusca, Neogastropoda, Conoidea) coletados no litoral sudeste do Brasil, Programa REVIZEE "Score" Central. Biociências (On-line) 13: 19–47

External links

Gardner J.A. (1937). The molluscan fauna of the Alum Bluff Group of Florida. Part VI. Pteropoda, Opisthobranchia and Ctenobranchia (in part). United States Geological Survey Professional Paper. 142-F: 251–435, pls 37–48
*
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. Texas A&M Press, College Station, Texas
* {{DEFAULTSORT:Compsodrillia Eucosmia eucosmia Gastropods described in 1889