(Linné, 1758)
Description (shell):
Shell solid, glossy, opaque; sculpture of spiral lines, crossed by longitudinal lines, with pigment distributed along some of the lines (S. lignarius-drawing).
Size:
Up to 45 mm. Total length up to 60 mm.
Colour:
Green, yellow, or brown.
Animal:
Body white or orange. Head very short, squat, indented anteriorly; tentacular processes smooth, short, conical. Parapodial lobes extending from anterior end of head shield to about middle of shell; pallial lobe also visible. Burrower, preying on infaunal worms and lamellibranchs (S. lignarius-animal).
Habitat:
In muddy sand; sublittoral, to 700 m.
Distribution:
Common in the North Sea (Distr. S. lignarius).