''Crassispira rudis'', common name the rustic pleurotoma, 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 Pseudomelatomina ...

Description

The length of the shell varies between 11 mm and 28 mm. (Original description) The thick, turreted shell is very dark brown, almost black. The whorls are contracted in the middle, tuberculated above and below, each of the lower tubercles having a white spot above it. 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 rather out of the centre. 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. The outer lip is thin, sinuous, armed above the sinus with a strong callosity Conchologia iconica, or, Illustrations of the shells of molluscous animals; Reeve, Lovell, Brooks, Vincent, Reeve, Frederic, Sowerby, G. B. (George Brettingham), Taylor, John Edward, Reeve Benham & Reeve, Savill, Edwards and Co., Spottiswoode & Co. Vincent Brooks, Day & Son, ; vol.1 (1843)

Distribution

This marine species occurs between the Sea of Cortez, Western Mexico and Ecuador

References

* G.B. Sowerby I (1833), Proc. Zool. Soc., p. 138

External links

* *
W.H. Dall (1909), Report on the collection of shells from Peru ;Proceedings of the United States National Museum, Vol. 37, pages 147–294, with Plates 20—28
{{DEFAULTSORT:Crassispira Rudis rudis Gastropods described in 1834