Polycera quadrilineata (Müller, 1776)

August 2000.
Out from Johnstone's Hole, Dunbar on the east coast.
A 16mm long, yellow and white specimen at 6.5 metres.

for more information about this species go to one of the links below
OPK - Opistobranquis nudibranchs of the british isles sea slug forum