Zool. [f. Gr. κεφαλή head + THORAX; see quot. 1835.] The anterior division of the body, consisting of the coalesced head and thorax, in certain Arachnida and Crustacea (as common spiders and crabs).
1835. Kirby, Hab. & Inst. Anim., The head and trunk … forming together what he [Latreille] names a cephalothorax.
1861. Blackwall, Spiders, I. Introd. 1. Spiders, with few exceptions, have a cephalo-thorax, or the head continuous with the chest.
1880. Huxley, Cray-Fish, 19. The fore part is termed the Cephalothorax.
Hence Cephalothoracic a.
1851. Richardson, Geol., viii. 260. The King Crabs … have the body covered with a large cephalo-thoracic shield.
1859. Todd, Cycl. Anat., V. 299/1. The cephalo-thoracic division.
