01 Testudinalia testudinalis. Littoral. Moray Coast, Banffshire, Scotland. May 2017. Leg. S. Taylor.

01 Testudinalia testudinalis. Littoral. Moray Coast, Banffshire, Scotland. May 2017. Leg. S. Taylor.

Lengths: 1) 11.6mm, 2) 12.1mm, 3) 13mm, 4) 13.2mm, 5) 14.2mm, 6) 12.1mm, 7) 13.9mm, 8) 12.2mm. Anteriors oriented upwards.
In Britain, sublittoral specimens usually grow up to 20mm long, 14mm wide, 10mm high, but 15mm is usual maximum length of intertidal specimens like these.