Rattus tiomanicus (Miller, 1900) . Proc. Washington Acad. Sci., 2:212.

TYPE LOCALITY: Malaysia, Pahang, Tioman Isl, off the east coast Malay Peninsula .

DISTRIBUTION: Endemic to the Sunda Shelf and some offshore islands. Records on the Shelf are from peninsular Thailand south of Isthmus of Kra (10°30'N), the Malay Peninsula, Sumatra, Java, Bali, Borneo, Palawan, and many smaller islands. Off the Sunda Shelf, R. tiomanicus is documented from Enggano Isl, southwest of Sumatra, and Maratua Arch., east of Borneo (Musser and Calafia, 1982; Musser and Heaney, 1985).

SYNONYMS: ambersoni, banguei, batin, blangorum, delirius, ducis, generatius, jalorensis, jarak, jemuris, julianus, kabanicus, kunduris, lamucotanus, lasurius, luxuriosus, maerens, mangalumis, mara, pauper, payanus, pemanggis, perhentianus, pharus, piperis, rhionis, roa, roquei, rumpia, sabae, sebasianus, siantanicus, sribuatensis, tambelanicus, tenggolensis, terutavensis, tingius, tua, vernalus, viclana.

COMMENTS: Reviewed by Musser and Califia (1982), who also summarized and provided references documenting the incorrect historical association of tiomanicus and the other synonyms listed here as subspecies of R. rattus . They also pointed out that a careful study of interisland variation among named forms of the R. tiomanicus complex is necessary before relationships among the insular populations can be discerned; more than one species, for example, may be represented in what is now viewed as R. tiomanicus .

Rattus mindorensis from Mindoro Island in the Philippines, R. simalurensis from the islands of Babi, Lasia, Siumat, and Simalule, off the northwest coast of Sumatra; and R. burrus from some of the Nicobar islands are also morphologically very similar to the R. tiomanicus complex and should be considered part of it (Musser, 1986; Musser and Heaney, 1985). Whether they are species or island forms of R. tiomanicus has yet to be determined.