_Souropatis cinnamominus_ Kuroda, in Momiyama, Birds Micronesia, 1922, p. 59 (Guam). _Hyposyma cinnamomina_ Mathews, Syst. Avium Australasianarum, 1, 1927, p. 384 (Marianne = Guam). _Halcyon cinnamomina cinnamomina_ Hand-list Japanese Birds, rev., 1932, p. 179 (Guam); Hand-list Japanese Birds, 3d ed., 1942, p. 200 (Guam); Mayr, Birds Southwest Pacific, 1945, p. 293 (Guam); Peters, Check-list Birds World, 5, 1945, p. 206 (Guam); Watson, The Raven, 17, 1946, p. 41 (Guam); Baker, Smithson. Misc. Coll., vol. 107, no. 15, 1948, p. 63 (Guam). _Halcyon cinnamomius_ Bryan, Guam, Rec., vol. 13, no. 2, 1936, p. 25 (Guam). _Geographic range._--Micronesia: Mariana Islands--Guam. _Characters._--Adult male: Head, neck, upper back, and entire under surface near "Sanford's brown"; auriculars black with bluish wash; narrow black line extending around nape; orbital ring black; lower back, lesser wing-coverts, and scapulars deep greenish-blue; outer webs of wing feathers and tail blue; rump resembles tail but slightly lighter; under wing-coverts greenish-blue; feet dark brown; bill black, base of mandible paler; iris dark brown. Adult female: Resembles adult male, but chin, throat, and upper breast paler; rest of underparts and under wing-coverts white; a few cinnamon-tipped feathers on tibia and at bend of wing; back and scapulars darker olive-green and less blue. Immature: Resembles adult, but brown of crown mixed with greenish-blue; back and wing-coverts edged with pale cinnamon; chin and throat whitish; rest of underparts buffy-white in male and paler in female; feathers on breast and nape with dark edgings. _Measurements._--Measurements are listed in table 32. TABLE 32. MEASUREMENTS OF _Halcyon cinnamomina_