1: Protruding, translucent, repugnatorial glands on the ventral face of the white mantle-border.
2: Ventral part of proximal face of the flat, folded cephalic shield.
3: Circular oral veil.
4: Orange tubular mouth, not everted and engorged for feeding.
5: Obliquely orientated, orange/yellow, probably respiratory, ribs corrugate the hyponotum (underside of mantle).
6: Sole of foot.
The inhalent respiratory current enters the gap held open at the rhinophores by the caruncle. It flows through the lateral lamellae (concealed in this image) and over the (probably respiratory) ribs in the large mantle cavity extending the length of the animal on either side.
Kolb (1998) called the cephalic shield an ‘oral veil’; citing her misreading of ‘oval’ in Schmekel & Portmann (1982) as ‘oral’. This image shows a circular oral veil which she and Thompson & Brown (1984) did not record, probably because they worked with preserved specimens that had greatly engorged mouths which concealed it.
Length 19.4mm. Ventral view. Sublittoral, Orkney, Scotland. May 2017. Leg. S. Taylor.