ARTHRITIS

inflammation of joints, usually a ociated with gout or rheumatism. ally symmetrical, segmented animals, having variously modified jointed appendages and a cuticle of chitin. NumerOus affinities exist between them and Annelids, notably in the division of the body into segments, the organization of blood-vascular and nervous system. A. are usually very active, and represent more than half the known species of animals. The chief cla es are Crustacea; Pro tot rache at a, including the primpedes and millipedes; Hexapod a, insects; A rach no idea, spiders, scorpions, and mites; Paloeostraca, the king-crab; and the extinct eurypterids and trilobites.