Seguenzia caliana is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae.
Seguenzia caliana Wikipedia
(Original description by W.H. Dall) The shell is small, its height attains 4.5 mm and its diameter is 3.2 mm. The white shell is elevated, trochiform, with a minute glassy smooth nucleus and about five subsequent whorls. The suture is obscure, and laid on the peripheral keel. On the spire there is a single sharp prominent keel somewhat behind the central line between the sutures, and on the body whorl is a similar peripheral keel with a wide excavated space on each side of it, the space behind the periphery wider. The base of the shell shows seven rather close-set squarish cords, those nearer the axis most adjacent to each other. The axial sculpture consists of low thin sharp lamellae with wider interspaces, over riding the peripheral keel on the spire but not on the body whorl. They are prominent in the interspaces behind the base, retractively arcuate in the posterior interspace, and protractively arcuate in the others. They do not invade the somewhat fiattish base. The aperture has a very deep sulcus nextto the suture. The outer lip in front of it is much produced, a feeble sulcus at the middle of the base. In front of the arcuate columella there is a smaller rounded indentation. Behind the columella there is a deep groove ending in a minutely perforate umbilicus. The body has no perceptible glaze.
This species occurs in the Pacific Ocean off La Jolla and San Diego, California.