Forbes, 1848
Description
External appearance
Solitary. Body globular to ovoid, up to 80 mm in diameter. Test heavily coated with sand, shells, etc., except for the siphons and the space between them.
Characters
Oral siphon 6-lobed; atrial siphon 4-lobed. Siphons placed close together. Branchial tentacles highly branched. Branchial sac with numerous rows of curved and spirally arranged stigmata; seven branchial folds; longitudinal bars present. Gut left of branchial sac; stomach narrow and small, not marked off from rest of gut, bearing many diverticula forming a complex liver. One gonad on each side, consisting of a central ovary with marginal male follicles. Oviduct short and directed towards the atrial siphon (M. oculata morphology).
Habitat
Unattached on sand or gravel; from low water level to about 80 meters.
Distribution
from the Shetland Islands down to the Bay of Biscay.
Remarks
This species has often been confused with Molgula occulta (see Berrill, 1950).