Hypotaenidia philippensis Salvadori (part), Ornith. Papuasia, 3, 1882, p. 261 (Pelew); Sharpe (part), Cat. Birds British Mus., 23, 1894, p. 39 (Pelew); Kuroda, in Momiyama, Birds Micronesia, 1922, p. 42 (Pelew).
Eulabeornis philippensis? Mathews, Birds Australia, 1, 1910-1911, p. 199 (Pelew).
Hypotaenidia philippinensis philippensis Hand-list Japanese Birds, rev., 1932, p. 196 (Palau).
Rallus philippensis pelewensis Hand-list Japanese Birds, 3d ed., 1942, p. 220 (Babelthuap, Koror); Mayr, Birds Southwest Pacific, 1945, p. 287 (Palau); Baker, Smithson. Misc. Coll., vol. 107, no. 15, 1948, p. 48 (Peleliu, Garakayo).
Geographic range.—Micronesia: Palau Islands—Babelthuap, Koror, Arakabesan, Garakayo, Peleliu, Angaur.
Characters.—Adult: A large, slender rail with black crown streaked with brown; superciliary stripe ashy-gray, lighter toward bill; eye stripe brown becoming more rufous behind eye and on nape; chin ashy-gray; throat near "mouse gray" tinged with olive especially toward breast; breast, belly and sides barred with black and white, with a broad "tawny" band on breast; posterior part of belly and vent buffy with some barring; under tail-coverts barred with black, white, and buff; mantle black with feathers subterminally barred with white; back, scapulars, inner wing-coverts, and rump black with white spotting and feathers edged with olive brown; outer wing-coverts, secondaries, and primaries barred with black and rufous with some buffy-white on outer webs; under wing barred black and white with some brownish markings; tail with both bars and blotches of black, white, and buffy-rufous; maxilla horn-colored; mandible yellowish; feet light brown.
R. p. pelewensis resembles R. p. philippensis Linnaeus of the Philippines, but is darker with nape more rufous-brown; upper parts marked with narrower and darker edgings to feathers and with pronounced whitish spotting.
Resembles R. p. chandleri (Mathews) of Celebes, but with wing shorter; more pronounced band on breast; bird darker above and below; rump and upper tail-coverts less spotted.
Measurements.—Specimens in the collection of the United States National Museum measure as follows: four adult males—wing, 130-134 (132); tail, 59-63 (61); full culmen, 30-37 (34); tarsus, 38-45 (43); four adult females—wing, 125-130 (127); tail, 54-61 (58); full culmen, 29-35 (32); tarsus, 38-42 (40). Mayr (1933c:4) lists the following measurements: twelve adult males—127-143 (134.6); tail, 54-65 (60); exposed bill, 25-28 (27.7); tarsus, 41-46 (43.5); three adult females—wing, 129, 136, 136; tail, 56, 57, 58; exposed bill, 23, 24, 25; tarsus, 40, 41, 42.