Proboscis when everted has in its wall an arrangement of muscle layers like that of the body wall (i.e. a middle layer of circular muscles between outer and inner layers of longitudinal fibres). Most have a somewhat flattened body, with often sharp and fin-like lateral edges. Some swim readily, with undulations in the sagittal plane. Cerebratulus has a horizontal slit along each side of the head, ending posteriorly in the aperture of a cerebral organ.
Source: Gibson and Knight-Jones, 1990.
The following taxa of this family occur in the region:
Genus Cerebratulus
Cerebratulus fuscus
Cerebratulus marginatus