Trivia monacha. Top left to bottom right: 6.5mm juv., 10mm juv., 12mm juv., 10.2mm adult, 12 mm adult. LWS Scapa Flow, Orkney, all on 26th April 1975, except 12mm adult 7th Sept 1975. The last juvenile stage can be larger than the early adult stage. Species Trivia monacha Photographer / copyright holder I.F. Smith
Trivia monacha adult shell cut open to show internal coiled juvenile shell. A very small rise on the outer adult shell indicates the position of the enveloped juvenile spire apex. LWS, Scapa Flow, Orkney Sept. 1975 Species Trivia monacha Photographer / copyright holder I.F. Smith
Trivia monacha adult shell. The central one of the three dark marks on the dorsum is indistinct on this specimen. 10.2 mm high (longest dimension). LWS, Scapa Flow, Orkney April 1975 Species Trivia monacha Photographer / copyright holder I.F. Smith
Trivia monacha adult shell. The diagnostic three dark marks on the dorsum are variable in intensity. Shell is shiny as protected from water much of the time by the mantle. Specimen 12 mm high (longest dimension). LWS, Scapa Flow, Orkney Sept. 1975 Species Trivia monacha Photographer / copyright holder I.F. Smith
Trivia monacha, live adult. Mantle fully extended. Dark marks on mantle are aligned with grooves in shell. LWS, Menai Strait, Wales. Aug. 2010. Species Trivia monacha Photographer / copyright holder I.F. Smith
Trivia monacha, live adult. Mantle half extended, lateral view. LWS, Menai Strait, Wales. Aug. 2010. Species Trivia monacha Photographer / copyright holder I.F. Smith
Trivia monacha, live adult. Mantle retracted, dorsal view. LWS, Menai Strait, Wales. Aug. 2010. Species Trivia monacha Photographer / copyright holder I.F. Smith
Trivia monacha, live adult. Mantle almost retracted, dorsal view. LWS, Menai Strait, Wales. Aug. 2010. Species Trivia monacha Photographer / copyright holder I.F. Smith
Trivia monacha, live adult. Mantle half extended, dorsal view. LWS, Menai Strait, Wales. Aug. 2010. Species Trivia monacha Photographer / copyright holder I.F. Smith
Lamellaria latens. Spire barely perceptible, does not protrude beyond outer lip of aperture when shell viewed in plan. Longest shell dimension 3.2mm, from an animal 7mm long when live. LWS, Menai Strait, Wales. Aug. 2010. Species Lamellaria latens Photographer / copyright holder I.F. Smith