Rissoa membranacea. Whitish, translucent flesh has much grey to brown-black pigment dorsally with opaque white spots. Snout is darkest laterally. Sides of body pigmented less intensely than dorsum. Translucent, whitish, slender, dorsolateral triangle (1) tapers towards the posterior. Surface pigment may obscure the opaque, white anterior pedal gland (2). Whitish mantle is often brownish near its edge (3) and greyish where it forms the posterior of the mantle cavity roof (4). H. 8.3 mm. Orkney, Scotland. May 2017. Leg. S. Taylor.