The class to which spiders belong. The body of the
spider is divided into the cephalothorax and the abdomen. The cephalothorax has
six pairs of jointed appendages. Spinnerets at the end of the abdomen are
projections through which the spider spins webs. Most spiders breathe by book
lungs. Other members of the class Arachnida are mites, ticks, scorpions,
horseshoe crabs,
and harvestmen.
