''Cratidentium balteata'', common name the tessellated top shell, is a

species In biology, a species is the basic unit of Taxonomy (biology), 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 ...

of sea snail, 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

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 es ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Trochidae The Trochidae, common name top-snails or top-shells, are a family of various sized sea snails, marine gastropod molluscs in the subclass Vetigastropoda. This family is commonly known as the top-snails because in many species the shell resembles ...

, the top snails.

Description

The height of the shell is 7 mm, its diameter 6 mm. The shell is solid for its small size, perforate, nearly exactly conical in form, and consists of 6

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 flo ...

s. The upper whorls are almost planulate, while the body whorl, which is as high as all the others together, is bluntly angulated. The upper whorls are encircled around their lower borders by a white girdle articulated with vertical black lines, and which is continued upon the periphery of the body whorl. Above this girdle are 5 elevated transverse lines, and upon the base about 12 inconspicuous ones. The

columella Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire. His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the ...

is almost vertical, rounded, with a slight tubercle in the middle, and forms an angle with the basal

lip The lips are the visible body part at the mouth of many animals, including humans. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech. Human lips are a tactile sensory organ, and can be ...

. The color of the shell is pale brown, and besides the above described girdle has large deep brown maculations below the suture. The spiral lirae are punctate with black. The base shows oblique streaks, formed by the coalescence of black dots.Tryon (1889), Manual of Conchology XI, Academy of Natural Sciences, Philadelphia
(described as ''Gibbula balteata'')

Distribution

This marine species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...

to Australia and occurs off

South Australia South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...

Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

and

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

References

* Philippi, R.A. 1849. ''Diagnosen mehrerer neuer Trochus arten''. Zeitschrift für Malakozoologie 9 6(10): 146-160 * Fischer, P. 1879. ''Diagnoses Trochorum novorum''. Journal de Conchyliologie 27: 22-25 * Pilsbry, H.A. 1889. ''Manual of Conchology''. Philadelphia : Academy of Natural Sciences Philadelphia Vol. 11 519 pp., pls 1-67 * 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=Q16975472 balteata Gastropods of Australia Gastropods described in 1849