Antedon bifida bifida (Pennant 1777)

Antedon bifida with P2 similar to and same length as P3 but with no gonad. P1 about twice as long as following two pinnules, of >25 segments. Cirri rarely >40, of up to 18 (usually 14 to 16) cirrals; distal cirrals moderately compressed, shorter and 1.5x wider than proximal cirrals, and slightly longer than broad;oximal ones. Interradial perisomic plates often present. First primibrachial very short, especially in larger specimens, with slightly converging lateral edges forming distinct angle with projecting lateral corners of axils.

Shetland and Orkney Islands S along coasts of Scotland, Ireland, Wales and England (except the coast of the North Sea between Northumberland and Straits of Dover), Atlantic coasts of France (S of Straits of Dover), northern Spain and most of Portugal. Depth range: low tide, and occasionally in tide pools and attached to floating objects, to 457 meters; most abundant in 15-40 m.