(Alder and Hancock, 1848)
Description
External appearance
Solitary. Body depressed and dome-shaped to cylindrical, up to 26 mm in diameter and 30 mm in height. Test wrinkled, with or without encrusting sand.
Characters
Both siphons 4-lobed. From 24-36 simple branchial tentacles of variable size. Branchial sac with numerous forws of straight stigmata; four branchial folds on each side. Gut left of branchial sac; stomach horizontal with longitudinal folds and a single small liver diverticulum. One gonad on each side of mantle wall, comprising a central ovary and separate, but adjacent male follicles (S. coriacea morphology).
Habitat
Attached to hard substrata; from shallow water down to at least 600 meters.
Distribution
Arctic Boreal distribution.