Colus griseus (Dall 1889)

How to Distinguish from Similar Species: Mohnia freilei, another rare subtidal species, has 12-15 axial ribs per whorl and only reaches 1.8 cm height.

As with other members of family Neptuneidae, this snail has a raised spire, a well-developed siphonal canal but the anterior portion of the body whorl and canal are not set off from the rest of the body whorl by a conspicuous groove. It has no anal notch, less than 8 whorls. Colus griseus is less than 3x as high as its diameter. It has both axial ribs and spiral ridges. The 23-28 low, broad axial ribs extend onto the body whorl but disappear or become indistinct on the anterior half of the body whorl. The spiral ridges are small and closely spaced and of similar size. The whorls do not have distinct angular shoulders. It has no folds on the columella nor on the inside of the outer lip of the aperture. The outer lip of the aperture has a concave curve where it meets the siphonal canal. The siphonal canal is less than half the total length of the aperture. The height is up to 3 cm.

Biology/Natural History: This is a rare subtidal species. While Kozloff classify this species in Family Neptuneidae, The American Fisheries Society and ITIS place it in family Buccinidae.

Geographical Range: Pacific

Colus griseus is a species of sea snail, a marine gastropod mollusc in the family Colidae, the true whelks and the like. It was first discovered in 1889.