1: Severn Estuary, England. 2: Dee Estuary, England. 3: Menai Strait, Wales. 4: illustration by A. Hancock (in Eliot, 1910). 5: Orkney.
L. depressa varies from yellowish to black, usually with small, random, paler marks. Most lack any large pale marks on the dorsum. Dorsally, there is no pale metapodium (‘tail’) visible, but a negligible one may be seen if the underside is slightly twisted into view (3). No digitiform tentacles, but most have a raised rim around the pale eye patches which Alder & Hancock (1862) in their original species description refer to as ‘lateral crests’, and which Hancock clearly illustrated (4). The rim varies in how much it is erected, being low when a specimen is not in good condition (2), and it may be difficult to discern in dorsal view of very dark specimens (5). Most subsequent authors omit or mistakenly deny the existence of the rim/crests on L. depressa.

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