This pill-woodlouse (to 12mm) is reminiscent of A. vulgare. However the narrow protruding scutellum (snout), reminiscent of the peak of a base-ball cap, is distinctive, as is the typically dark grey body marked with pale longitudinal stripes that give a semi-translucent appearance. It forms an imperfect ball, with its antennae protruding, when disturbed.
Distribution and Habitat
It occurs patchily across southern England and south Wales. It is characteristic of dry, sparsely vegetated habitats, both semi-natural and synanthropic, that are subject to high levels of insolation. This includes coastal grassland, limestone screes, disused limestone quarries, railway lines, industrial waste ground and garden centres (where it frequently occurs inside greenhouses).
It is typically found under rocks, stones, pieces of wood and other debris or amongst rubble, often with A. vulgare.
This summary is based on the detailed account in Gregory (2009).