1: translucent mantle (other features seen through it).
2: thickened mantle edge.
3: mantle extension forming respiratory inhalant siphon (unrolled in right image).
4: osphradium at base of siphon.
5: ctenidium.
6: hypobranchial gland containing greenish hypobranchial mucus.
7: rectum.
8: black rectal gland.
9: heart.
10: kidney.
11: visceral lump containing digestive gland and, in breeding season, ovary.
12: efferent vessel of ctenidium.
13: cephalic tentacles.
14: operculum.
From shell height 28 mm. Llŷn Peninsula, Wales, March 2016.
: flic.kr/p/2op3qCC
Sets of OTHER SPECIES:
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