The ventral surface of the head consists of two large, flat, fleshy lips which open along T-shaped slits for the inner lips with mouth and jaws to be brought forward to cut the prey.
There are prominent, slender, curved propodial tentacles; they and the anterior of the foot, which they are continuous with, are bilaminate. Couthouy (1838) seems to have regarded them as “labial or oral appendages – – – which are entirely separate from the foot and extend across it and beyond it”; but this image shows that they are part of the foot and not of the head or mouth.
Outer Hebrides, Scotland. April 2018. Leg. D. McKay & S. Taylor.