Centipedes, millipedes, and their kin are collectively called myriapods. Centipedes are carnivores, and have one pair of jointed legs per body segment, which never have 100 segments, but vary from 30 to 354. Millipedes have two pairs of jointed legs per body segment, up to 333 in number, and mostly feed on decaying plant material. Myriapods are arthropods and share a common ancestor with the crustacea, that includes insects, which in turn share a common ancestor with the arachnids. Arthropods have an exoskeleton, a segmented body, and paired, jointed appendages. They have highly developed sense organs. 84% of all species on the Earth are arthropods. Crustacea generally have two pairs of appendages (antennules and antennae) in front of the mouth and paired appendages near the mouth that function as jaws. They occupy a wide range of habitats, and many are aquatic, although the largest group in terms of number of species, the insects, are mainly terrestrial. Woodlice are common crustaceans in gardens.
Earthworms are annelids, evolving on a separate lineage to the arthropods, but they share a common ancestor with the molluscs. The Annelida is a large group of segmented worms, also called ring worms. Molluscs are a large, diverse group of invertebrates, which have unsegmented bodies enclosed within calcareous shells, and are represented in gardens mainly by terrestrial gastropods such as snails and slugs. Other molluscs, particularly the bivalves and cephalopods, are aquatic. Representatives of all these groups are found in the cemetery.
