How snails breathe through snorkels on land

Shells with a tube counterintuitively sealed at the top have overlooked powers

shells of Alycaeus conformis snail

COUNTERINTUITIVE SNORKELS  Little tubes (arrows) following the crease between whorls let these small Asian Alycaeus snails breathe when hiding in their shells — even though tube ends are sealed.

B. Páll-Gergely

Microscope work may have solved the puzzle of Asian snails’ “useless” snorkels.