This is a small white, to off-white, woodlouse, reaching 4mm. The eyes consist of a prominent single black ocellus, its colour retained in alcohol, and the entire body is covered in coarse spiny tubercles.
The coastal Trichoniscoides saeroeensis is similar in appearence, but has reddish/orange ocelli, which rapidly lose their colour in alcohol, and the dorsal surface is less coarsely tuberculate.
Distribution and Habitat
Although never common, this species occurs widely along the southern coasts of England and Ireland with outlying populations as far north as eastern Scotland.
It is exclusively coastal, primarily associated with pockets of damp friable peaty soil occurring in supralittoral habitats, such as salt marsh, sparsely vegetated shingle banks, erosion banks and at the base of sea cliffs. It is frequently found associated with other soil-dwelling trichoniscids, such as Trichoniscoides saeroeensis and Trichoniscus pygmaeus.
This summary is based on the detailed account in Gregory (2009).