O. vulgaris with two rows of dark-edged, white, circular suckers on purplish red underside of each arm(1). No rim around the lateral periphery of the mantle (2) . Surface of mantle and head almost smooth (3). Opening to mantle cavity (4). Exhalant funnel protruding from mantle cavity to eject water to propel it (5).
Falmouth, Cornwall, England, in unusually hot summer, August 2022 © J. Chatfield.