''Gymnobela emertoni'' 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

Raphitomidae Raphitomidae is a family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Bouchet P. & Rocroi J.-P. (Ed.) (2005). "Classification and nomenclator of gastropod families". ''Malacologia'' 47(1-2). . 39 ...

Description

The length of the shell varies between 14 mm and 27 mm. (Original description) The shell is moderately large, stout and ovate. 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 ...

is very large in proportion to the rest of the shell. Some of the upper

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 are ribbed and nodulous, while the two lower whorls have only spiral lines and lines of growth. The shell contains about eight whorls, three of which form a chestnut-colored

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 ...

. About three whorls below the protoconch are covered with prominent, longitudinal ribs, which form a well marked shoulder and are crossed by several conspicuous, revolving cinguli and grooves, which render them decidedly nodulous. The subsutural band is broad, strongly concave, occupying nearly or quite half the breadth of the upper whorls, and is crossed by strongly receding, raised lines, parallel with the lines of growth of the sinus, but without spiral lines. The body whorl is large and swollen, covered throughout with very evident lines of growth, which are crossed, except on the subsutural band, by conspicuous, revolving cinguli, which are separated by spaces considerably exceeding their own breadth. The aperture is oblong-ovate, scarcely narrowed at the broad, short, open

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 with a very wide and rather deep posterior sinus. The outer lip is thin and projects well forward beyond the sinus in a broadly rounded curve. The columella is straight, with a sinuous inner margin. The inner lip is marked by a narrow and thin enamel, which extends but little forward in a sinuous outline. The color is yellowish white under a thin, smooth, glossy, yellowish green epidermis. 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(1): 139-294, pl. 28-32

Distribution

This marine species occurs on the Mid-Atlantic Ridge and off New Jersey and Virginia, USA.

References

* Sysoev A.V. (2014). Deep-sea fauna of European seas: An annotated species check-list of benthic invertebrates living deeper than 2000 m in the seas bordering Europe. Gastropoda. Invertebrate Zoology. Vol.11. No.1: 134–155 * 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

Verrill A. E. (1885). Third 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: 395-452, pl. 42-44

MNHN, Paris: ''Pleurotoma leptoconchum''
*
Locard, A., 1897 - Mollusques testacés. In: Expéditions scientifiques du Travailleur et du Talisman pendant les années 1880, 1881, 1882, 1883, vol. 1, p. 516 p, 22 plsBouchet & Warren, Revision of the North-East Atlantic bathyal and abyssal Turridae (Mollusca, Gastropoda); The Journal of Molluscan Studies, supplement 8, December 1980
{{DEFAULTSORT:Gymnobela Emertoni emertoni Gastropods described in 1884