Caesia perpinguis
Caesia perpinguis is a species of  snail, a marine gastropod mollusk in the family Nassariidae.

Description
(Described as Nassa interstriata) The ovate-acute shell contains 5½ whorl. These are rounded and cancellated. The longitudinal striae are nodulous, except towards the base of the body whorl. A deep sulcus behind the aperture, two upper whorls are entire. The outer lip is striated within. The spire is conical and is longer than the aperture.

The surface of this shell is roughened by a tubercle on the longitudinal, at each intersection of the revolving lines. 

(Described as Nassa perpinguis var. bifasciata) This is a color form of Nassa perpinguis Hinds., which is strikingly distinct and is certainly worthy of a varietal name if color forms must be named. It differs from the ordinary form in the presence of two broad spiral bands of a deep chestnut color in abrupt contrast to the grayish-buff ground color of the shell. One of these bands is situated just below the suture, one about the periphery, and occasionally a fainter band makes it appearance at the extreme base of the body whorl. The bands vary considerably in width, but no specimens having but a single band.

Distribution
This species was found in Magdalena Bay, western coast of Mexico; also in the Persian Gulf.

References

 Marrat, F. (1877). On some proposed new forms in the genus Nassa. Liverpool, privately printed, 15 pp., 1 pl

External links
 Mollusca types in Great Britain: photo
 Conrad, T. A. (1855). Description of the fossil shells. In: United States. War Department (1853-1856). Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean. 5: 317-328.
 Melvill, J. C. (1918). Descriptions of thirty-four species of marine Mollusca from the Persian Gulf, Gulf of Oman and Arabian Sea, collected by Mr. F. W. Townsend. Annals and Magazine of Natural History. ser. 9, 1: 137-158, pls 4-5
 Adams, A. (1852-1853). Catalogue of the species of Nassa, a genus of gasteropodous Mollusca belonging to the family Buccinidae, in the collection of Hugh Cuming, Esq., with the description of some new species. Proceedings of the Zoological Society of London. (1851) 19: 94-112

Nassariidae
Gastropods described in 1844