''Mohnia parva'' 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, which are the true whelks.

Description

The length of the shell varies between 14 mm and 27 mm. The small, thin, delicate shell is translucent, subfusiform. It contains a rather slender, 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 ...

; a short, straight

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 ...

; and a few raised, strong, revolving cinguli. The suture is impressed. It has six to seven convex whorls, usually with three (rarely five or six) prominent, rounded cinguli, or carinae, separated by much wider, broadly concave interspaces. The uppermost one is usually some distance below the suture, and is often stronger than the rest, producing a slight shoulder. 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 ...

, in specimens with six whorls, there are about seven to nine principal carinae, occasionally with a smaller one interpolated, and becoming more crowded anteriorly. On one specimen with seven whorls, there are thirteen principal cinguli. Fine, delicate and close, raised lines of growth, or lamellae, cover the interspaces and cross the raised cinguli. 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 very small, smooth and glossy. The first whorl is minute and regularly spiral, not upturned. Three spiral cinguli appear on the second whorl. 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 elliptical. The thin outer lip is rounded, incurved at the base of the siphonal canal, which is narrow, but very short, and straight. The columella is nearly straight in the middle. The

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...

is thin, lamellose, but not ciliated. The color is yellowish or grayish white. The operculum is ovate, with the outer or left end rounded and incurved, forming a small lobe, defined by a notch, and with the nucleus central to this small lobe. The

odontophore The odontophore is part of the feeding mechanism in molluscs. It is the cartilage which underlies and supports the radula, a ribbon of teeth. The radula is found in every class of molluscs except for the bivalves. The feeding apparatus can be exte ...

is very slender. The outlines of the median plates are indistinct. They bear three very small but distinct and nearly equal denticles. The lateral teeth of the

radula The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

have only two denticles. Verrill, A. E. 1882. Catalogue of marine Mollusca added to the fauna of the New England region, during the past ten years. Transactions of the Connecticut Academy of Arts and Sciences 5: 451–587, pls. 42–44, 57–58

Distribution

This marine species lives off

New England New England is a region comprising six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York to the west and by the Canadian provinces ...

in the United States

References

* Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca. in: Costello, M.J. et al. (eds), European Register of Marine Species: a check-list of the marine species in Europe and a bibliography of guides to their identification. Patrimoines Naturels. 50: 180–213

External links

* {{DEFAULTSORT:Mohnia Parva Buccinidae Gastropods described in 1882