Puffinus pacificus cuneatus Mathews, Birds Australia, 2, 1912, p. 84 (Marshall Group); Peters, Check-list Birds World, 1, 1931, pp. 55-56 (Krusenstern); Hand-list Japanese Birds, 3d ed., 1942, p. 209 (Krusenstern); Fisher, Auk, 63, 1946, pp. 587-588 (Ailuk).
Thyellodroma cuneata cuneata Mathews and Iredale, Ibis, 1915, p. 597 (Krusenstern); Mathews, Syst. Avium Australasianarum, 1, 1927, p. 113 (Marshall Group).
Thyellodroma cuneata Oberholser, Auk, 34, 1917, p. 474 (Krusenstern).
Thyellodroma pacificia cuneata Mathews, Novit. Zool., 39, 1934, p. 186 (Caroline Islands).
Geographic range.—Pescadores east to the Hawaiian Islands and south to eastern Micronesia. In Micronesia: Marshall Islands—Ailuk.
Remarks.—Osbert Salvin received two specimens of this shearwater from H. J. Snow, who got them at the Krusenstern Islands in 1883. In describing them, Salvin (1888:353) comments that the locality is seemingly in the Marshall Islands at approximately 10°17´ N. and 190° W. This locality was confusing to Seebohm (1891:191) who thought it was between the Hawaiians and the Marshalls, while Hartert (1926:352) decided it was really Krusenstern Rocks in the Hawaiian Group. To clear the matter up, Fisher (1946:587-588) writes that Salvin was correct and suggests that the name of the island should be the better established one, Ailuk, rather than the little used one, Krusenstern.
P. p. cuneatus resembles P. p. chlororhynchus but is whiter on the underparts, especially the breast. These two subspecies are inseparable according to the twenty-fourth supplement to the American Ornithologists' Union Check-list of North American Birds (Auk, vol. 66, 1949:281).