Alvania pariana
Alvania pariana is an extinct species of minute sea snail, a marine gastropod mollusc or micromollusk in the family Rissoidae.
Description
The length of the shell attains 2.3 mm, its diameter 1.5 mm.The turreted shell is conic-oblong. It contains about 6 whorls. They are decorated by about 4 spiral ribs narrower than their interstices, upon which rise into points somewhat stout longitudinal costae, forming subquadrate or oblong pits, in which some faint striae may be observed. The apex is smooth. The base has about 4 spiral ribs. The outer lip is stout and expanded.