Diodora fargoi
Diodora fargoi is a species of sea snail, a marine gastropod mollusk in the family Fissurellidae, the keyhole limpets and slit limpets.
Description
The shell reaches a length of up to about 9 mm and is short, conical, and fairly solid, with the length nearly twice the height. The apex is bluntly truncated and perforated by an oblong to slightly trilobate orifice situated in the anterior third of the shell. The posterior slope is longer and distinctly convex, while the anterior slope is shorter, steeper, and nearly straight.The basal margin is oblong-ovate and weakly concave medially, with a coarsely serrated edge formed by the projecting ends of the ribs. Shell sculpture is strongly cancellate, consisting of coarse radial ribs crossed by concentric threads. There are nine primary radial ribs on each side, with smaller secondary and tertiary riblets in the interspaces. The concentric sculpture includes coarse primary ridges and finer threads, producing sharp nodules at their intersections.
The exterior colour is cream to light greenish grey, irregularly mottled with black; the secondary riblets are often dark. Internally, the callus surrounding the orifice is well developed, sharply truncated posteriorly, and white to grey in colour.