Common striped woodlouse  (Philoscia muscorum )

Abdomen: in arthropods (crustaceans, insects and arachnids) the abdomen is the hind region of the body, which is usually segmented to a degree (but not visibly in most spiders). In crustacea (e.g. crabs) some of the limbs attach to the abdomen; in insects the limbs are attached to the thorax (the part of the body nearest to the head) and not the abdomen. In vertebrates the abdomen is the part of the body that contains the internal organs (except the heart and lungs).
Crustaceans: diverse group of arthropods (a phylum of animals with jointed limbs and a hard chitinous exoskeleton) characterised by the possession of two pairs of antennae, one pair of mandibles (parts of the mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, slaters, woodlice and barnacles.
Thorax: part of the body located near the head in animals. In insects, the three segments between the head and the abdomen, each of which has a pair of legs.

1. NBN Species Dictionary (Jan 2003):
   http://nbn.nhm.ac.uk/nhm
   
2. Woodlice- Natural History Museum (March 2004):
   http://www.nhm.ac.uk/hosted_sites/woodlice/photos/philoscia_muscorum.html
   
3. Sutton, S. L. (1972) Invertebrate types: woodlice. Ginn & Company Ltd., London.
   
4. The pied piper (March 2004):
   http://www.the-piedpiper.co.uk/th11c(3).htm
   
5. Woodlice online (March 2003):
   http://www.geocities.com/CapeCanaveral/Hangar/7649/wliceod.htm