Borsonella agassizii

Species of gastropod

Borsonella agassizii

Original drawing of a shell of Borsonella agassizii
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Neogastropoda
Superfamily:	Conoidea
Family:	Borsoniidae
Genus:	Borsonella
Species:	B. agassizii
Binomial name
*Borsonella agassizii* (Dall, 1908)
Synonyms^[1]
Borsonia (Borsonella) agassizii Dall, 1908

Borsonella agassizii is a species of sea snail, a marine gastropod mollusk in the family Borsoniidae.^[1] The snail was named after Louis_Agassiz.

Description

The length of the shell attains 23 mm.

(Original description) The shell is biconic. The aperture is shorter than the spire. The apex is eroded but with six remaining whorls. The color of the shell is white and chalky under a pale greenish yellow periostracum. The suture is distinct, not appressed. The whorls are sloping flatly to the periphery which is marked by a rounded keel with (on the body whorl fifteen) obscure elongated swellings or undulations. The anal fasciole which is close to the suture is marked by lines of growth concavely arcuate, crossed by half a dozen spiral incised lines in the path of the sulcus. Below the keel are lines of growth, obscure traces of spiral distant incised lines, and numerous irregularly impressed striae, which are perhaps pathological. The base of the shell is moderately convex. The outer lip is thin, sharp, strongly protractive below the keel, above the latter with a wide, shallow anal sulcus reaching close to the suture. The body is polished, milkwhite. The columella is short, twisted, white, with a well-marked spiral plait near its insertion. The siphonal canal is wide, short, distally funicular, and somewhat recurved.^[2]

Distribution

This species occurs in the Pacific Ocean off the Gulf of Panama and the Galapagos Islands.

References

^ ^a ^b Borsonella agassizii (Dall, 1908). Retrieved through: World Register of Marine Species on 13 August 2011.
^ 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)