Large white cnidosac (1) slightly tinted by reddish integument above dark contents of digestive gland (2). Anterior cerata have dark contents only in basal sections (3). Rest of each ceras is occupied by large white cnidosac (4) and pale digestive gland (5). Red tinting not intense, so general colour is whitish and resembles the white ruff of A. alderi (6).

Menai Strait, Wales, September 2009.