''Mohnia carolinensis'' 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 ...

Buccinidae, the true whelks.

Description

The length of the shell attains 15 mm, its diameter 7 mm. (Original combination) The small shell is pretty regularly fusiform. It has an elevated, rather acute

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spires are ...

, which forms nearly one-half the total length of the shell. It contains six to seven moderately convex

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 an impressed suture. The

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 ...

consists of about twelve rather prominent, stout longitudinal ribs, wliicli run nearly straight across the whorls. And 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 ...

these extend to the base of the siphon. These are separated by deeply concave intervals of about the same width. The whole surface is covered by strongly marked revolving cinguli, which cross both the ribs and their interspaces, and thicken so as to form small, rounded nodules where they cross the ribs. These are separated by interspaces of about the same width, in the middle of which there is a much smaller, thin revolving cingulus, alternating pretty regularly with the larger ones around the periphery. On the anterior part of the body-whorl, and sometimes at the periphery, there are two or three small revolving cinguli in some of the interspaces. On the penultimate whorl there are usually five to seven of the primary cinguli, and on the

and siphon there are about eighteen to twenty. The whole surface is also covered, in perfect specimens, with fine, slightly elevated, wavy lines of growth, which are most conspicuous on the intervals between the ribs. They are usually worn off from the more prominent parts of the ribs and nodules. 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 ...

consists of about 2½ regularly coiled whorls. The first two are small, smooth, translucent and somewhat lustrous. The last is covered with rather faint revolving lines, crossed by the lines of growth, which gradually merge into the longitudinal sculpture of the normal whorls, there being no very distinct demarcation between the protoconch and the next whorl. The apical whorl is minute, regularly increasing. 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 ...

is elongated, ovate-fusiform; The outer lip is thin, sharp and regularly curved. The inner margin is regularly arched. The columella is somewhat elongated, its margin sinuous and somewhat excurved at the tip. 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 ...

is narrow and somewhat elongated, a little curved. The color of the shell is bluish white. The epidermis is very thin, pale grayish or yellowish white.Verrill, A. E. 1884. ''Second catalogue of Mollusca recently added to the fauna of the New England coast and the adjacent parts of the Atlantic, consisting mostly of deep-sea species, with notes on others previously recorded.'' Transactions of the Connecticut Academy of Arts and Sciences 6: 139–294, pls. 28–32.

Distribution

This species occurs in the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

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.

External links

* {{DEFAULTSORT:Mohnia Carolinensis Buccinidae Gastropods described in 1884