(Montagu, 1803)
Description (shell):
Shell with a tall spire, with five slightly rounded whorls and the protoconch; smooth except for few prosocline growth lines on last whorl, no keel but slight angle to last whorl. Whorls dipping very slightly into sutures. Aperture elongate, rather angular; columellar tooth well-developed and conspicuous (O. unidentata-drawing).
Size:
Up to 3.8 mm.
Colour:
White to off-white or greyish.
Distribution:
Common in the North Sea (Distr. O. unidentata).