"The coloration is in general dull black, brownish black on head and wings, chin and upper throat are dark slate colored lighter in the middle. The under wing and tail-coverts are marked with scattered white spots (querflecken). The first primary has an irregular whitish brown margin on the outer web. The bill is dark and the feet yellowish."
Possibly this rail represents an ancient colonization of Kusaie from an ancestral stock of Porzana in Polynesia. Mayr (1941b:203) is also of this opinion, and if this is true there is no close relationship between Aphanolimnas and the rails at Guam and Wake, Rallus owstoni and R. wakensis, which are probably colonizers from the Philippines or the Papuan area. Mayr (1943:46) remarks further that the Hawaiian flightless rail (Peuula) is of doubtful taxonomic position, but may be related to the "Aphanolimnas-Porzanoidea-Nesophylax stock," although there is no evidence that Pennula is not related to Rallus. Supposed colonization routes are shown in [figure 9].
Poliolimnas cinereus micronesiae Hachisuka
White-browed Rail
Poliolimnas cinereus micronesiae Hachisuka, Bull. British Ornith. Club, 59, 1939, p. 151. (Type locality, Yap.)
Ortygometra quadristrigata Hartlaub and Finsch, Proc. Zool. Soc. London, 1868, pp. 8, 118 (Pelew); idem, Proc. Zool. Soc. London, 1872, pp. 90, 107 (Pelew, Uap).
Ortygometra cinerea Finsch, Journ. Mus. Godeffroy, 8, 1875, pp. 5, 38 (Palau, Yap); idem, Proc. Zool. Soc. London, 1880, p. 577 (Ruk); Salvadori, Ornith. Papuasia, 3, 1882, p. 273 (Yap, Pelew); Wiglesworth, Abhandl. und Ber. Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p. 61 (Pelew, Yap, Ruk); Finsch, Deut. Ver. zum Schulze der Vogelwelt, 18, 1893, p. 459 (Palau).
Ortygometra cinerea = quadristrigata Schmeltz and Krause, Ethnogr. Abth. Mus. Godeffroy, 1881, p. 353 (Ruk).
Poliolimnas cinereus Sharpe, Cat. Birds British Mus., 23, 1894, p. 130 (Pelew, Yap, Ruk); Hartert, Novit. Zool., 5, 1898, p. 64 (Guam); idem, Novit. Zool., 7, 1900, p. 9 (Ruk); Scale, Occ. Papers Bernice P. Bishop Mus., 1, 1901, p. 30 (Guam); Safford, Osprey, 1902, p. 67 (Mariannes); idem, The Plant World, 7, 1904, p. 265 (Guam); idem, Contr. U. S. Nat. Herb., 9, 1905, p. 79 (Guam); Cox, Island of Guam, 1917, p. 21 (Guam); Kuroda, in Momiyama, Birds Micronesia, 1922, p. 42 (Guam, Pelew, Yap, Ruk).
Porzana cinerea Stresemann, Novit. Zool., 21, 1914, p. 54 (Guam, Truk).