''Cryptogemma periscelida'', common name the Atlantic gem 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 ...

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

Turridae Turridae is a taxonomic family name for a number of predatory sea snails, marine gastropod mollusks in the superfamily Conoidea. MolluscaBase (2018). Turridae H. Adams & A. Adams, 1853 (1838). Accessed through: World Register of Marine Specie ...

, the turrids.MolluscaBase eds. (2020). MolluscaBase. Cryptogemma periscelida (Dall, 1889). Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=1425549 on 2020-10-16

Description

The length of the shell varies between 25 mm and 50 mm. (Original description by W.H. Dall) The stout shell has a fusiform shape. It is covered with a straw-colored epidermis. It is elaborately sculptured and contains 10

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, exclusive of 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 ...

The spiral sculpture consists of: * (1) a cord at first rounded and irregularly constricted at short intervals, later flattened with numerous transverse waves and indentations. This band becomes gradually wider, has two small grooves along its center, and at the sides, especially the sutural side, it overhangs the channels on each side of it. From the first this band conceals the suture, toward the end 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 ...

it becomes less prominent and descends slightly. *(2) a broad elevated band grooved centrally and covered with twin nodules in pairs one above the other, which on the later whorls are somewhat reniform. This band represents the fasciole or pathway of the square-cut anal notch. *(3) in the channel between the two last are two small, elevated, rounded nodulous cords. *(4) in front of the fasciole and on the base of the body whorl are four or five strong spirals, and between these and in front of them 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 ...

are numerous smaller ones, all crossed and roughened by the transverse ridges of growth. One or two of these spirals are visible on the whorl before the last, the earlier ones not showing any of the basal spirals. Transverse sculpture consists of coarse elevated incremental lines more or less visible over the whole shell. The aperture is rather wide The siphonal canal is narrow and slightly curved. The outer lip shows a deep notch squared at the bottom, then strongly arched forward, later contracted for the siphonal canal. The columellar margin is simple and sharp. The inner lip is white, smooth, simple and slightly excavated . Inside the outer lip are six or eight strong lirae falling short of the margin. The columella is nearly straight, attenuated and twisted in front, making the end of the siphonal canal flare a little. There is no umbilical trace. This species is one of the most remarkable and elegant of any from the deeper waters. It belongs to the group of which ''Pleurotoma speciosa'' Reeve forms a member, by its sculpture, though whether the nucleus would agree with that species is uncertain. At present our judgment on such subdivisions as ''Gemmula'' Weinkauff, founded on nuclear characters, must be held suspended. So far as our knowledge goes, nuclear characters have little absolute systematic value in this group, and their relative value remains to be determined.

Distribution

''C. periscelida'' can be found in Atlantic waters, ranging from the coast of North Carolina south to

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

.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

External links

Dall W.H. 1889. Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Gulf of Mexico (1877-78) and in the Caribbean Sea (1879-80), by the U.S. Coast Survey Steamer "Blake", Lieut.-Commander C.D. Sigsbee, U.S.N., and Commander J.R. Bartlett, U.S.N., commanding. XXIX. Report on the Mollusca. Part 2, Gastropoda and Scaphopoda. Bulletin of the Museum of Comparative Zoölogy at Harvard College, 18: 1-492, pls. 10-40.

Zaharias P., Kantor Y.I., Fedosov A.E., Criscione F., Hallan A., Kano Y., Bardin J. & Puillandre N. (2020). Just the once will not hurt: DNA suggests species lumping over two oceans in deep-sea snails (Cryptogemma). Zoological Journal of the Linnean Society. DOI: 10.1093/zoolinnean/zlaa010/5802562
* {{DEFAULTSORT:Cryptogemma Periscelida periscelida Gastropods described in 1889