Milne-Edwards, 1841
Description
External appearance
Colonial, with zooids immersed. Colonies forming fleshy, round, pear-shaped or flat-topped lobes of up to 30 mm across. Each lobe with one or few cloacal openings. Common test yellow-grey or yellow-brown, usually coated with sand.
Characters
Zooids up to 6 mm in length; body divided into thorax, abdomen and post-abdomen. Oral siphon 6-lobed; atrial siphon with long languet. Branchial sac with 10-16 rows of straight stigmata; transverse vessels bearing minute papillae. Gut abdominal; stomach smooth. Gonads located in post-abdomen, consisting of small ovary covered by numerous male follicles (P. aurantium zooid).
Habitat
Attached to hard substrata; from lower shore to about 100 meters.
Distribution
From Norway to the Mediterranean.