OENITHOLOGirAL EXPLORATIONS 285 



1850.— MofadUa ocularis SwiNH., Ibis, 1860, p. 5^.— Id., ihicl, 1863, pp. 94,^09.— Id., 

 P. Z. S., 1863, p. 27r>.—Id.,ilml.,lH7l, p. 364.— Taczan., J. f. Orn., 1873, p. 

 82.— Id., ibid., 1874, p. 335.— /d., ibid., 1875, p. 252.— M, Bull. 8oc. Zool. 

 France, 1876, p. 1^0.— Id.,ibid., 1882, p. 389.— M, Orn. Fauna Vost Sibir., p. 

 33 (1876).— Seebohm, Ibis, 1878, p. 345.— Tf?., ibid., 1883, p. 92.— Id., ibid., 

 1884, p. 39.— KiDGW., Pr. U. S. Nat,. Mus., 1881, p. 414.— /rf.. ibid., 1883, p. 145 

 {2yart). — Bean, ibid., 1882, p. 147.— Nelson, Cruise Corwin, p. 62, pi. 

 (1883).— Stejneger, N.atnren, 1884, p. 5. — Blakist., AniPucL List B. Jap., p. 

 54(l8tt4). 



1871. — Motacilla baicalensis var. temporalis Swinh.,P. Z. S., 1871, p. 363. 



On the 10th of June, 1882, 1 obtained on Bering Island a Gray -backed 

 Wagtail, the sex of which could not be determined, and which at the 

 time was referred to the same species as the other Wagtails {lugens), the 

 last of which, in 1883, were observed just a month previous. 



This late appearance led to a careful comparison, after my return to 

 Washington, the result of which was that I now consider it to belong to 

 ocularis. 



As I have only one specimen of the latter species in good summer 

 plumage, it must be admitted that my material has been rather scanty,* 

 but as it agrees pretty closely with my Bering Island bird, not only in 

 size but also in all the other points in which the former differs from 

 typical summer specimens from Kamtschatka, it is thought that the 

 conclusions arrived at are correct. It is next to be remarked that the 

 difference of time between the date of the two birds is only sixteen days, 

 and that the specimens from Kamtschatka selected for the compax'ison 

 are the gray-backed females, one of which was killed only sixteen days 

 earlier in the season than the Bering Island bird, and furthermore that 

 the specimen of ocularis was collected by E. W. Nelson at Plover Bay, 

 on the Tschuktschi Peninsula, and designated as a malef (U.S. Nat. 

 Mus. No. 89676). 



As already stated, the specimens from Bering Island and Plover Bay 

 agree completely as to size and coloration,! so that any detailed compari- 

 son between them is superfluous. In these two specimens the back is 

 " absolutely uniform plumbeous-gray." But placed alongside the Kam- 

 tschatkan specimens a brownish tinge is quite perceptible, while in the 

 latter the color is purer bluish and occasionally clouded with blackish, 



* I have since had the opportunity of comparing large series and find uiy conclusions, 

 as set forth in the following, fully substantiated. 



tAs both sexes of ocularis have the back gray in summer, there is no reason for sup- 

 posing that the determination of the sex of the present specimen is erroneous (c/. 

 Kidgw., Pr. U. S. Nat. Mus., 1883, p. 146). 



X Cf. also Ridg way's statement {I. c.) that No. 89676 "agrees minutely with No. 

 88988 in coloration." 



