Hiatella arctica. Mantle edge whitish. 2 worn radial ribs to posterior. Periostracum covers siphons, part of fused whitish mantle lobes, and shell, except one worn area. Substantial byssus. Menai, March 2011. Species Hiatella arctica Photographer / copyright holder I.F. Smith
H. arctica. Fused siphons; inhalent taking in water, exhalent closed so siphons swollen and periostracum stretched thin. Two worn ridges, with some spines, run radially from beak to posterior. Wedge-form shell. Byssus near anterior. Menai, March 2011. Species Hiatella arctica Photographer / copyright holder I.F. Smith
Hiatella rugosa. Ruby, red, and orange siphon tips protruding from limestone. Menai Strait, April 2011. Species Hiatella rugosa Photographer / copyright holder I.F. Smith
Hiatella rugosa. Siphon tips protruding from limestone. Specimen on right has siphons closed while they are expanded to brace against sides of hole during boring activity. Small burrows with mud tube extensions made by Polydora worms. Menai Strait Species Hiatella rugosa Photographer / copyright holder I.F. Smith
Hiatella rugosa. Dorsal (except smallest) view of specimens extracted from limestone borings. Menai Strait, April 2011. Species Hiatella rugosa Photographer / copyright holder I.F. Smith
H. rugosa. Mantle lobes sealed except for small opening for foot; sucker-like. Top left: tip of foot showing, and rounded anterior gape of shell resembles Zirfaea crispata. Bottom left; emitting milt as temperature rose during photography. Menai Strait. Species Hiatella rugosa Photographer / copyright holder I.F. Smith
Hiatella rugosa in situ in limestone boring, rock split open. b: lower face of narrow outer boring, bored when juvenile. s: siphon tip of neighbouring specimen projecting from rock surface. Menai Strait, April 2011. Species Hiatella rugosa Photographer / copyright holder I.F. Smith
Hiatella rugosa. Periostracum covers siphons, and much survives on valves; difficult to explain if boring action into solid limestone is by mechanical movement of valves unaided by chemical or muscular action of foot. Species Hiatella rugosa Photographer / copyright holder I.F. Smith
Chlamys varia. Attached to underside of stone on Menai Strait, Aug. 2010. Mantle edges with sensory tentacles and mirror eyes (lens and reflecting mirror) of use because does not burrow. Comb-like ctenidium visible through gape of mantle lobes. Species Chlamys varia Photographer / copyright holder I.F. Smith
Lepidochitona cinerea. vg: rounded valve granules. gg: rounded girdle granules. gf: girdle fringe of blunt fusiform spines. Menai Strait, midshore. February 2011 Species Lepidochitona cinerea Photographer / copyright holder I.F. Smith
