cephalothorax
From ZooTerms (Dictionary of Invertebrate Zoology)
Arthropoda) A descriptive term used for many arthropods indicating the anterior region of the body combining head and thorax; sometimes used to denote fusion with one or more of the thoracic segments, as in crustaceans and coccids; for arachnids, see prosoma.
cephalothorax (noun; Greek kephale, head; thorax, chest): (