Adaptation
The Helicodiscus parallelus is a
terrestrial Gastropod of the subclass Pulmonata, which is
distinguishable by the use of pneumatostomes, openings used to
take in oxygen. Pulmates have lost their anscestral gill
and the mantel now serves as a large lung
(Nordsieck, R.).
Also, the Compound Coil has no visible eyes/eyespots. This
is because of the snail's subterranean habitat, where there is
no advantage to having a sense of sight. They spend the
majority of their time within the thin splits of damp, rotting
wood, this is likely why the operculum is at such an aggressive
angle, to allow for easier movement and feeding
(Pisbry, 1890).