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 (no͞o′mə-stōm′, nyo͞o′-)
A small opening in the mantle of a pulmonate gastropod through which air passes.

[From New Latin pneumostoma : pneumo- + Greek stoma, mouth.]
References in periodicals archive ?
This caused the snails to open up their pneumostome (breathing tube) to get oxygen from the air.
When the snail opened its pneumostome at the surface, it was given a gentle poke with a wooden stick, causing it to close again.
than identified by Harry and Hubendick (1964), they are described in terms of their association with (i) the upper portion of neck and head, (ii) the lung floor and pneumostome and (iii) the columellar muscle.
According to Lukowiak, the snails breathe through their skins when oxygen levels are high, but when oxygen levels drop the snails extend their pneumostomes above the water's surface to supplement the supply.