Moelleria costulata
Moelleria costulata, common name the ribbed moelleria, is a species of sea snail, a marine gastropod mollusk in the family Colloniidae.

Description
The size of the shell varies between 0.5 mm and 2.6 mm. The shell is ribbed longitudinally.

Distribution
This marine species occurs in circum-Arctic waters, off Alaska, in European waters, the Northwest Atlantic Ocean and down south to Morocco.