Right: intact animal extracted from shell.
Left: roof of mantle cavity severed along its right side and lifted to expose its underside.
1: anterior of both specimens.
2: roof of cavity is transparent with dark marks; thinness facilitates respiratory gas exchange.
3: network of vessels which transport colourless haemolymph (blood) through the roof of the mantle cavity to lose carbon dioxide and acquire oxygen.
4: floor of mantle cavity (seen through mantle) which is raised/lowered to increase/lower air pressure in the cavity to exhale/inhale respiratory air through the pneumostome (respiratory pore).
5: rectum.
6: kidney.
7: foot.
8: ureter carrying urine from kidney to enter mantle cavity near anus. Both faeces and excreta leave the mantle cavity with the exhalent current out of the pneumostome.

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