Murphy (1927:6-15) revised the shearwaters of the _Puffinus lherminieri_ group, and recognized several subspecies. _P. l. dichrous_ was assigned a range consisting of Micronesia, the Phoenix Islands, and Nauru Island. The breeding range of _P. l. polynesiae_ was given as the Samoan, Society, Tuamotu and Marquesas islands. Color differences between the two subspecies are very slight, and he separated them on the basis of the length of the exposed culmen as follows: _P. l. dichrous_ 22.6-27 (26) in _P. l. polynesiae_ 25.5-30 (28.9). In other measurements they closely resembled one another. At the time of his study, Murphy did not have the shearwaters from Micronesia collected by Coultas and actually did not have a large series from these islands. On studying this new material, I find the length of the exposed culmen of 17 adult birds from Micronesia (including 12 from the Palaus) to be 26-30 (27.9). In comparison with Murphy's findings, my measurements of Micronesian birds fall almost midway between the measurements which he recorded as characteristic of _P. l. dichrous_ (from the Phoenix Islands) and _P. l. polynesiae_. The intermediate position of the measurements of the Micronesian birds, together with the absence of other distinguishing characters, suggests that these shearwaters belong to only one subspecies which consists of a group of isolated and variable populations. Unless the old specific name, _obscuras_ of Gmelin, is revived, the name for the entire group in Micronesia and Polynesia would be _P. l. dichrous_. I agree with Murphy that the Bonin form, _P. l. bannermani_, is a well-defined subspecies. =Pterodroma rostrata rostrata= (Peale) Tahiti Petrel _Procellaria rostrata_ Peale, U. S. Expl. Exp., 8, 1848, p. 296. (Type locality, Mountains about 6,000 feet on Tahiti, Society Islands.) _Procellaria desolata_ Pucheran, Voy. Pôle Sud, 3, 1853, p. 138 (des îles Carolines); Hartlaub, Journ. f. Ornith., 1854, p. 168 (Carolinen). _Procellaria (Aestrelata) desolata_ Gray, Cat. Birds Trop. Is. Pacific Ocean, 1859, p. 55 (Caroline Islands). _Oestrelata rostrata_ Wiglesworth, Abhandl. und Ber. Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p. 82 (Caroline Is.); Godman, Monogr. Petrels, pt. 3, 1908, p. 190 (Caroline Is.). _Pterodroma rostrata_ Kuroda, in Momiyama, Birds Micronesia, 1922, p. 33 (Carolines). _Pterodroma rostrata_ subsp. (?) Hand-list Japanese Birds, rev., 1932, p. 188 (Carolines); Hand-list Japanese Birds, 3d ed., 1942, p. 210 (Carolines). _Geographic range._--Known to breed on the Society and Marquesas Islands. In Micronesia: Caroline Islands--exact locality unknown.