D. coronata (Gmelin, 1791).
1: subepidermal red pigment ln mesial face of cerata on adults.
2: red, slightly tinted violet, surface mottling extends laterally to below the cerata but not onto the cream-white dorsal surface of the foot.
3: each ceras has up to four concentric rings of rounded tubercles, often with an indistinct partially formed fifth ring at base.
4: each tubercle has a red apical spheroid and several white granular bodies. No pigment marks on the surface of the cerata.
Dee Estuary, England. February 2017