Planorbis corinna

Planorbis corinna is a species of minute, air-breathing freshwater snail, an aquatic pulmonate gastropod mollusc, or micromollusc in the family Planorbidae, the ram's horn snails, or planorbids. All planorbids have sinistral or left-coiling shells.

Distribution
This species is endemic to New Zealand.

Shell description
This species, like all planorbids, has a sinistral shell. The shell in this species is very minute, discoidal, with four slowly increasing whorls. The shell coloration is greenish-white to light brown. The width of the shell is up to 3.3 mm, and the height is up to 0.8 mm.