Facelina bostoniensis (Couthouy, 1838)

10 August, 2003.
Rubh' aird Phlacaig, Loch Etive on the west coast. 
At 12 metres in 12° C water, a 40mm long animal among a number of Flabellina lineata.
Olympus C2020-Z in PT-010 housing with Nikonos 105 flash.

for more information about this species go to one of the links below
OPK - Opistobranquis

 nudibranchs of the british isles sea slug forum