_Phaëthon aethereus mesonauta_ Peters, Occ. Papers Boston Soc. Nat.
Hist., 5, 1930, p. 261. (Type locality, Swan Key, Almirante Bay,
Panama.)
_Phaeton aethereus_ Finsch, Ibis, 1880, pp. 329, 333, (Ratak
Chain, Marshalls); _idem_, Journ. f. Ornith., 1880, p. 310
(Kuschai); _idem_, Ibis, 1881, p. 109 (Kuschai); Wiglesworth,
Abhandl. und Ber. Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p.
73 (Kushai, Marshalls); Ogilvie-Grant, Cat. Birds British Mus. 26,
1898, p. 457 (Kushai, Marshalls); Schnee, Zool. Jahrbücher, 20,
1904, p. 390 (Marschall Inseln); Kuroda, in Momiyama, Birds
Micronesia, 1922, p. 34 (Kusaie, Marshall Islands).
_Phaethon aethereus [?mesonauta]_ Hand-list Japanese Birds, rev.,
1932, p. 187 (Kusaie, Marshalls); Hand-list Japanese Birds, 3d
ed., 1942, p. 208 (Kusaie, Marshall Islands).
_Geographic range._--Tropical parts of Atlantic and eastern Pacific
from Cape Verde Islands west to Panama and Galapagos Islands. In
Micronesia: Caroline Islands--Kusaie; Marshall Islands--Ratak
Chain.
_Characters._--Adult: A large, white sea bird with a long white
tail; dorsal surface marked with blackish, transverse
vermiculations; bill red; tarsus and foot flesh-colored with a
yellowish hue, with plantar surface grayish. Immature: Resembles
adults but dark transverse bars are broader; crown blacker; bill
yellow.
_Remarks._--No specimens have been examined. The Red-billed Tropic-bird
is placed in the list of birds known from Micronesia on the basis of
two observations by the German ornithologist, Otto Finsch. It has not
been reported since his time, and may be considered as an unusual record
for the area. I am following the Hand-list of Japanese Birds (Hachisuka
_et al._, 1942:208) in assigning the bird to the subspecies, _P. a.
mesonauta_.
=Phaëthon rubricauda rothschildi= (Mathews)