Alvania verrilli
Alvania verrilli is a species of small sea snail, a marine gastropod mollusk or micromollusk in the family Rissoidae.
Distribution
This marine species occurs in the lower Estuary of St. LawrenceDescription
The maximum recorded shell length is 2.9 mm.The white, solid shell is ovo-elongate. It contains 5 convex whorls. The protoconch is obtuse and smooth. The suture is deep. The aperture is sub-circular. The sculpture consists of, about 20 strongly prominent axial ribs, and a microscopically minute and close spiral striation. There is no umbilicus but only a minute umbilical split. The outer lip is thickened.
The peculiar fine spiral sculpture causes this species to be readily distinguishable.