Rattus adustus Sody, 1940. Treubia, 17:397.

TYPE LOCALITY: Indonesia, Pulau Enggano, off the coast of W Sumatra (and off the continental shelf), Kiojoh, sea level.

DISTRIBUTION: Known only from Enggano Isl.

COMMENTS: Known only by the holotype. Although Sody (1940) described adustus as a species of Rattus, he later listed it as a subspecies of R. rattus in a section also containing lugens and mentaivai, populations endemic to the Mentawai islands (Sody, 1941). The Enggano rat is distinctive; in morphology and geographic proximity it is related to R. lugens (Musser and Heaney, 1985).