Pl. terga. The Latin word for ‘back’ (synon. with DORSUM): in special scientific uses. a. The back, or upper surface or portion, of an arthropod or other articulated animal; more usually, the upper plate of each somite or segment of such an animal (= TERGITE): opp. to sternum. b. Each of the two upper plates of the shell in cirripeds.
1826. Kirby & Sp., Entomol., III. 387. Tergum, the upper or supine surface of the abdomen.
1851. Darwin, Cirripedia, Introd. (Palæont. Soc.), 2. In almost all the Lepadidæ the Terga (i.e. the upper or posterior lateral valves) are not characteristic.
1880. Huxley, Crayfish, iii. 96. Each ring [of the abdomen] consists of a dorsal, arched portion, called the tergu, [etc.].
