Berkeley in Sars, 1851
Description:
Body small with up to 35 chaetigers; 6-9 thoracic chaetigers.
Four pairs of radioli; tips of radioli are not swollen. Two dorsal radioli form a peduncle with pinnules and bear distally a soft, cup-shaped, asymmetrically developed operculum. Two thick palps.
Collar notched in the centre of the ventral margin.
Peristomium with two eyes.
Collar chaetae of two types, straight capillary chaetae and bent chaetae with a toothed fin and a finely serrated blade. Fin with large teeth distally and smaller ones proximally.
The following thoracic segments with straight, toothed capillaries and sickle-chaetae.
Thoracic uncini with 2-3 rows of small teeth and a large terminal tooth. Apomatus-chaetae starting at chaetiger 3, usually one per bundle.
A relatively long part of the body between thorax and abdomen without segmentation and chaetae.
Abdominal neuropodial chaetae are geniculate with finely toothed blade. Uncini with several longitudinal rows of small teeth (F. implexa-detail).
Size:
Up to 5-7 mm long for 30-60 segments.
Tube:
Fine with occasional growth rings, often forming shallow incrustations (F. implexa). Very similar to that of Salmacina dysteri .
Colour:
Red or orange coloured, posteriorly often greenish. Crown transparent or basis reddish.
Habitat:
Crevices in rock, onPentapora , sublittoral. Forms large colonies.
Distribution:
World-wide. English Channel, northern and southern North Sea, Skagerrak, Kattegat and northern Öresund.