''Conticosta petilinus'' 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

Pseudomelatomidae Pseudomelatomidae is a family of predatory sea snails, marine gastropods included in the superfamily Conoidea (previously Conacea) and part of the Neogastropoda ( Bouchet & Rocroi, 2005). In 1995 Kantor elevated the subfamily Pseudomelatominae ...

, the turrids and allies.

Description

The length of the shell attains 12.5 mm, its diameter 4.6 mm. (Original description) The thin shell is lanceolate and sub-turreted. Its surface is smooth and glossy. The colour is buff-yellow, with two zones of raw sienna, the one subsutural, the other peripheral. The shell 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 flo ...

s, of which two constitute 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 ribs are prominently round-backed, arranged at ten to a whorl. They follow each other irregularly up the spire. On the upper whorls the spirals are evanescent, and are represented by two or three beads on the ribs. 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 ...

there are about fifteen slight wide-spaced threads. The fasciole is indistinct. The aperture has a semi-circular sinus. The outer lip is simple and slightly bent inwards 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 ...

is short, and slightly recurved. Hedley, C. 1922. A revision of the Australian Turridae. Records of the Australian Museum 13(6): 213–359, pls 42–56

Distribution

This marine species is endemic to Australia and occurs off New South Wales

References

* Powell, A.W.B. 1966. ''The molluscan families Speightiidae and Turridae, an evaluation of the valid taxa, both Recent and fossil, with list of characteristic species''. Bulletin of the Auckland Institute and Museum. Auckland, New Zealand 5: 1–184, pls 1–23

External links

* {{DEFAULTSORT:Conticosta Petilinus petilinus Gastropods described in 1922 Gastropods of Australia