Ariadnaria borealis
Ariadnaria borealis, commonly referred to as the boreal hairysnail, is a species of small sea snail, a marine gastropod mollusk in the family Capulidae, the cap snails.
Distribution
This species occurs in the North Sea, the Canadian part of the Arctic Ocean, in the Northwest Atlantic Ocean; circumpolar in the Arctica, the White Sea, and in the Pacific from Peter the Great Gulf and northern Japan.Description
The maximum recorded shell length is 22 mm.The shell has a rather oblong shape, featuring three to four whorls that are somewhat rounded. It is equipped with three or four not very prominent, obtuse keels, with smaller intervening striae that are crossed by the lines of growth. The columella and the siphonal canal immediately below it are somewhat more elongated than in the previous species. The umbilicus is also slightly more expanded, making it less linear compared to the Trichotropis bicarinata. Along its edge and on the keels of the exterior of the shell, the epidermis presents numerous bristle-like appendages.