''Borsonella omphale'' 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 Borsoniidae
Borsoniidae is a monophyletic family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Bouchet, P. (2011). Borsoniidae. Accessed through: World Register of Marine Species at http://www.marinespecies.o ...
.
Description
The slender shell is acute, with eight flattish
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 exclusive of the (lost) nucleus. Its color is white covered by a very light olive gray
periostracum
The periostracum ( ) is a thin, organic coating (or "skin") that is the outermost layer of the shell of many shelled animals, including molluscs and brachiopods. Among molluscs, it is primarily seen in snails and clams, i.e. in gastropods and ...
. The
suture is distinct. The fasciole is hardly impressed. The spiral sculpture consists of obscure striae, sparser on the base. The axial sculpture consists of incremental faint lines arcuate on the anal fasciole. The
aperture is narrow. The anal sulcus is wide and moderately deep. The outer
lip is thin, prominently arcuate in front of the periphery. The inner lip is erased. The
columella is strong with a single fold near the
body ; attenuated in front. 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 height of the shell is 16 mm ; of 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 ...
: 10 mm; diameter: 6 mm.
Dall (1919) Descriptions of new species of Mollusca from the North Pacific Ocean; Proceedings of the U.S. National Museum, vol. 56 (1920)
(described as ''Borsonella nychia'')
Distribution
This species occurs in the Pacific Ocean off Santa Barbara Island, California.
References
* Tucker, J.K. 2004 ''Catalog of recent and fossil turrids (Mollusca: Gastropoda).'' Zootaxa 682:1–1295.
* McLean J.H. (1996). ''The Prosobranchia''. In: Taxonomic Atlas of the Benthic Fauna of the Santa Maria Basin and Western Santa Barbara Channel. The Mollusca Part 2 – The Gastropoda. Santa Barbara Museum of Natural History. volume 9: 1–160
External links
*
{{DEFAULTSORT:Borsonella Omphale
omphale
Gastropods described in 1919