The mantle cavity is closed by a collar of thickened mantle (1) that has a pneumostome (respiratory pore) (2) which can be opened for inhalation/exhalation of air and closed to seal the cavity against dehydration. Faeces from the anus and excreta from the kidney are deposited in the mantle cavity and expelled from the pneumostome. The pneumostome operates both when the animal is extended or retracted. Faeces (3) white as specimen had eaten white card.

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