Alvania compacta

Alvania compacta is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae.

Description
The length of the shell varies between 2 mm and 3 mm.

It is sculptured like Alvania beanii, but with short, broad whorls.

(Described as Rissoia acutelirata) The thin shell has a brownish ash-color. Its sculpture shows about 18 longitudinal, distant ribs, vanishing on the periphery, crossed by distant spiral lirae (15 on the body whorl). The shell is not nodose. It contains six convex whorls, rapidly enlarging, with a well-impressed suture.

Distribution
This species occurs off Alaska, USA to Northern Baja California, Mexico