prosoma

prosoma (noun; Greek pro, before; soma, body): 1. (Arthropoda) The anterior part of the body, usually applied to the cephalothorax.

2. (Arthropoda: Chelicerata) Fused imperceptably to the opisthosoma in Acari

See also: proterosoma. 3. (Arthropoda: Crustacea) Commonly limited by the major articulation; in barnacles, large saclike body in position of head in front of, and rostrad to, thoracic appendages; prosome. 4. (Arthropoda: Insecta) The head and the two succeeding fused segments of Coccoidea.