‖n. pl. [ Neut. pl. from L. articulatus furnished with joints, distinct, p. p. of articulare. See Article, v. ] (Zool.) 1. One of the four subkingdoms in the classification of Cuvier. It has been much modified by later writers. [ 1913 Webster ]

☞ It includes those Invertebrata having the body composed of a series of ringlike segments (arthromeres). By some writers, the unsegmented worms (helminths) have also been included; by others it is restricted to the Arthropoda. It corresponds nearly with the Annulosa of some authors. The chief subdivisions are Arthropoda (Insects, Myriapoda, Malacopoda, Arachnida, Pycnogonida, Crustacea); and Anarthropoda, including the Annelida and allied forms. [ 1913 Webster ]

2. One of the subdivisions of the Brachiopoda, including those that have the shells united by a hinge. [ 1913 Webster ]

3. A subdivision of the Crinoidea. [ 1913 Webster ]