The NAMRU2 field parties found _H. brevipes_ as singles or in small groups of five or less. They remained apart from other species and appeared to prefer rocky beaches and coral-reef rocks to the sandy beaches. At Guam in 1945, the latest spring migrants were taken on May 29. These birds were in nuptial plumage. Birds taken at Bikini by Morrison on February 26 and April 28, 1946, were in worn, winter plumage. At Guam, the NAMRU2 observers obtained the first fall migrants on September 19. These observations in 1945, showed that _H. incanus_ arrived at Guam on its southbound flight fully one month after the first individuals of _H. brevipes_ began to appear (mid-July). This difference may partly result from the fact that the distance to the Asiatic breeding grounds of _H. brevipes_ is not so great as that to the American breeding grounds of _H. incanus_. Whether the two tattlers, _H. brevipes_ and _H. incanus_, are distinct species (allopatric species insofar as breeding ranges are concerned), or whether they are mere subspecies (geographic races) is open to question. I failed to find evidences of intergradation in the few specimens which I examined critically; however, the final answer to the problem might be obtained by collecting series of birds from breeding grounds where ranges closely approach each other or overlap (if they do). Stickney (1943:6, 7) lists the distinctive differences in these two birds, particularly the character of the nasal groove, and does not mention having found any evidence of intergradation. Wetmore (in Townsend and Wetmore, 1919:180) gives evidence that they belong to two separate species. =Arenaria interpres interpres= (Linnaeus) Turnstone _Tringa Interpres_ Linnaeus, Syst. Nat., ed. 10, 1, 1758, p. 148. (Type locality, Europe and North America, restricted to Gotland, Sweden.) _Tringa interpres_ Quoy and Gaimard, Voy. "Uranie," Zool., 1824, p. 708 (Guam). _Strepsila collaris_ Kittlitz, Obser. Zool., in Lutké, Voy. "Le Séniavine," 3, 1836, pp. 287, 299, 304 (Ualan, Lougounor, Guahan); _idem_, Denkw. Reise russ. Amer. Micron. und Kamchat., 2, 1858, p. 32 (Ualan).