hal·o·bac·te·ri·um 
(hăl′ō-băk-tîrē-əm)
(hăl′ō-băk-tîrē-əm)n. pl. hal·o·bac·te·ri·a (-tîrē-ə)
Any of various rod-shaped, halophilic, pigmented archaea of the genus Halobacterium, some of which produce bacteriorhodopsin to facilitate ATP synthesis during periods of oxygen deficiency.
[New Latin Halobactērium, genus name : HALO- + BACTERIUM (from the fact that archaea such as halobacteria were formerly classified as bacteria).]