''Ithycythara acutangulus'' is a species of
sea snail, a marine
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 ...
Mangeliidae
Mangeliidae is a monophyletic family of small to medium-sized, predatory sea snails, marine gastropod mollusks in the superfamily Conoidea.
Bouchet, P. (2011). Mangeliidae P. Fischer, 1883. In: MolluscaBase (2016). Accessed through: World Reg ...
.
Description
The length of the shell attains 7.5 mm, its diameter 2.5 mm.
(Original description) The white shell has an elongate subfusiform shape.
This species is remarkable for the acute angulations of the eight
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 spiral liration at the angle, and the purplish-red bands at the suture and the middle of the body whorl, the latter being visible within 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 ...
, which measures about ⅓ of the total length. The number of ribs appears to vary from seven to eight; and they are not quite regularly continuous from the
apex
The apex is the highest point of something. The word may also refer to:
Arts and media Fictional entities
* Apex (comics), a teenaged super villainess in the Marvel Universe
* Ape-X, a super-intelligent ape in the Squadron Supreme universe
*Apex, ...
downwards. The outer
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 ...
is incrassate and hardly sinuate. 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 narrow and very short.
Smith, E.A. (1882) Diagnoses of new species of Pleurotomidae in the British Museum. Annals and Magazine of Natural History, series 5, 10, 206–218
Distribution
References
External links
Bouchet P., Kantor Yu.I., Sysoev A. & Puillandre N. (2011) A new operational classification of the Conoidea. Journal of Molluscan Studies 77: 273–308
Tucker, J.K. 2004 ''Catalog of recent and fossil turrids (Mollusca: Gastropoda)''. Zootaxa 682:1–1295
acutangulus
Gastropods described in 1882
{{Mangeliidae-stub