''Crosseola striata'' 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 ...

of small

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 ...

micromollusc A micromollusk is a shelled mollusk which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine mollusks, although in addition, numerous species of land snails and freshwater mollusks also r ...

, a

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

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 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 ...

Conradiidae Conradiidae is a taxonomic family (created in 1987 by Golikov & Starobogatov) of very small sea snails, marine gastropod molluscs or micromolluscs. These genera were previously included in the polyphyletic family Skeneidae. They belong with ...

Description

(Original description by R. Boog Watson) The height of the shell attains 1.5 mm, its diameter 1.3 mm. The very small, porcellaneous white shell has a turbinate shape. It is spirally striated, with a raised, subscalar

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 minute rounded apex, which is tabulated, with the extreme tip just visible, a tumid

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 ...

, and a small strongly bordered umbilicus.

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 ...

: Longitudinals—there are microscopic lines of growth which gather into puckers below the suture. Spirals—there are furrows broadish and square-cut, parted by flat raised surfaces of about twice their breadth. These extend to below the periphery, but not to the base, the most of which is smooth. Round the umbilicus is a high raised thread, which relatively to the size of the shell is enormous. The four

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 well rounded, and a very little tabulated below the suture. The body whorl is tumid. The suture is strongly marked, but hardly impressed. 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 round, but a little gibbous, bluntly pointed above. The thin, well arched outer lip is scarcely patulous. The inner lip is regularly curved from the corner of the aperture to the point of the columella, which is arched, with a thin inner edge parting the aperture from the umbilicus and joining the outer lip, while round the umbilicus twists the strong marginal cord which runs out into a strong blunt tooth at the tip of the columella. The deep umbilicus is small but strongly marked. The Journal of the Linnean Society of London v.16 (1881-1883)

Distribution

This marine species occurs off

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

and Australia (

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an states and territories of Australia, Australian territory in the central and central northern regions of Australia. The Northern Territory ...

)

References

* Watson, R.B. 1883. ''Mollusca of "H.M.S. Challenger" expedition''. Journal of the Linnean Society of London, Zoology 16: 494 * Thiele, J. 1925. ''Gastropoda der Deutschen Tiefsee-Expedition. II. Teil. Wissenschaftliche Ergebnisse der Deutschen Tiefsee-Expedition auf dem Dampfer "Valdivia" 1898–1899'' 17(2): 35-382, pls 313-346 * Cotton, B.C. 1959. ''South Australian Mollusca. Archaeogastropoda. Handbook of the Flora and Fauna of South Australia.'' Adelaide : South Australian Government Printer 449 pp. {{Taxonbar, from=Q5188546 striata Gastropods described in 1883