Aeolidiella sanguinea
Slender sinuous body with part of notum exposed for much of the length of the body. Body, rhinophores and cerata are translucent red, with no opaque freckles on notum. Internal eye visible (other hidden by ceras).
All cerata have a large white cnidosac slightly tinted by the red surface of the cerata. The front row of cerata forms a white ruff tinted red.
Distance between oral tentacles about same as thickness of single tentacle base.
Anterior edge of foot sigmoid terminating in short propodial tentacles with tips bent forwards. No surface pigment on oral tentacles or cerata, but rhinophores have distinctly demarcated white tips.
Menai Strait, Wales, September 2009.