page_title: Glomeris marginata
section_title: Description
hierarchical_section_title: Glomeris marginata / Description
caption_attribution_description: English: cf. Glomeris marginata, Darmstadt, Germany
context_page_description: Glomeris marginata is a common European species of pill millipede. It is a short millipede, rounded in cross-section, which is capable of rolling itself up into a ball when disturbed. This behaviour is also found in the pill woodlouse Armadillidium, with which G. marginata is often confused.
context_section_description: Glomeris marginata grows up to 20 millimetres (0.8 in) long and 8 mm (0.3 in) wide, and is covered by twelve black dorsal plates with white rims. Each segment except those at the front and back bears two pairs of legs, with around 18 pairs in total. This distinguishes pill millipedes from pill woodlice, both of which are called "pillbugs" — woodlice have 7 pairs of walking legs, one per body segment, while millipedes have more pairs, and with two pairs to each apparent body segment.
  When rolled into a ball, G. marginata can be distinguished from a rolled–up pill woodlouse by the asymmetrical ball it rolls into; pill woodlice roll into much more perfect spheres. The cuticle is also darker and shinier, and the antennae are shorter. The head and tail of a woodlouse have a greater number of small plates, while the head of Glomeris is protected by a single large shield, and it lacks the uropods of woodlice at the read end. Although usually black, red, yellow and brown individuals do occasionally occur.
caption: The underside of G. marginata – note the two pairs of legs per body segment
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