Eubranchus farrani (Alder & Hancock, 1844)

5 January, 2013.
North Bay Reef, Loch Fyne on the west coast.
9 mm animal at 19 metres. Water temperature 9° C.
Sony NEX-5 in Nauticam housing, 18-55mm lens with Subsea +10 dioptre and 2 x Inon D-2000 flashes.