''Borsonella diegensis'' 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

Length of four whorls, 15.0 mm; of body whorl, 12.5 mm ; of aperture, 9.5 mm ; max. diam. 8.0 mm. (Original description) The small shell is stout, solid, decollate, with a whitish substratum and strong olivaceous periostracum. The four remaining

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 are closely coiled and have the aperture longer than the remaining portion of the spire. The sculpture consists of a strong spiral keel, peripheral on the spire with more or less nodulation (in cue specimen with fifteen small nodules on the penultimate whorl, but none 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 ...

; another has them obsolete on the spire), stronger on the earlier whorls when present, an obscure ridge in front of the suture, stronger on the earlier whorls. There is a faint spiral striation on the anal fasciole between the ridge and the keel. The whole surface is covered with a microscopic, close, impressed, vermicular network of fine lines anastomosing in every direction. On the body whorl the keel is well above the periphery. The base of the shell is evenly rounded. The aperture is ample. The anal sulcus at the suture is wide and deep. The thin outer lip is arcuately produced. The columellar lip is smooth, with a glaze of callus. The plication on the proximal part of the columella lags behind the aperture. 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 very wide and short and has an obsolete fasciole. W.H. Dall (1908): Reports on the Dredging Operations off the West Coast of Central America to the Galapagos, to the West Coast of Mexico, and in the Gulf of California, in charge of Alexander Agassiz, carried on by the U. S. Fish Commission Steamer "Albatross," during 1891, Lieut. Commander Z. L. Tanner, U. S. N., Commanding. XXX VII. Reports on the Scientific Results of the Expedition to the Eastern Tropical Pacific, in charge of Alexander Agassiz, by the U. S. Fish Commission Steamer "Albatross," from October, 1904, to March, 1905, Lieut. Commander L. M. Garrett, U. S. N., Commanding. XIV. The Mollusca and the Brachiopoda; Bulletin of the Museum of Comparative Zoology at Harvard v. 43 p. 275 (1904)
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Distribution

This species occurs in the Pacific Ocean off California.

References

{{DEFAULTSORT:Borsonella Diegensis diegensis Gastropods described in 1908