Arion occultus

Arion occultus is a species of small air-breathing land slug, a terrestrial pulmonate gastropod mollusk in the family Arionidae, the roundback slugs.

Distribution

This species occurs in:

Ireland; appears to be introduced in Ireland, but its country of origin is not known.

Description

This recently recognized species is part of the "Arion hortensis group" of species. It somewhat resembles Arion distinctus in general appearance, and also resembles Arion alpinus, but the internal anatomy of the reproductive system is different.