534 Birds of Celebes: Motacillidae. 



The Eastern and Western forms of M. flava are equally entitled to sub- 

 sjjecific distinction in virtue of the difference in the hind claw; if so separated 

 the Eastern form would have to bear the name M. flava flaveola (Pall.). It is 

 also extremely doubtful whether M. borealis and M. cinereicapilla Savi do not 

 intergrade with the forms of M. flava. 



The Blue-headed Yellow Wagtail is a winter visitor to Celebes, though 

 individuals remain there, apparently, all the year. Meyer met with it at 

 Limbotto in July, and the adult male described supra was shot by Platen on 

 June 16'\ 1878, in South Celebes. Everett mentions it as a regular winter 

 migrant found throughout the N. W. coast of Borneo from September to May, 

 and Whitehead saw it in "thousands" on the Tampassuk plains. During his 

 expedition to Palawan the latter naturalist first saw it on IS"" September, "when 

 the vanguard passed in a south-westerly direction. In October they were still 

 migrating in hundreds, but were mostly young birds" (16). M. flava came on 

 board Meyen's ship on the China Sea between China and Luzon (3, 4), and 

 Mr. Finn (Ibis 1893, 225) mentions specimens, which he took for this species, 

 as having settled on his steamer in the Mediterranean and Red Sea, while 

 Mr. Hartert (a Sj writes that specimens accompanied his steamer from the 

 south coast of Arabia all the way to Acheen Head in Sumatra, so making the 

 journey from west to east. In Pegu Mr. Oates found it to be rather a rare 

 winter visitor. It passes through Central China, according to Mr. Sty an (20), 

 on migration in spring and autumn, but the Abbe David (a 2), whose obser- 

 vations were made more in the northern part of the country, writes that it is 

 common in China from spring to the end of autumn and particularly abundant 

 in summer in Mongolia. It was not known to Seebohm (18) from Japan 

 in 1890. 



It breeds in Kamtschatka where Taczanowski (a 7) describes it as not 

 rare, but in Dauria Dybowski and Godlewski found it rather scarce. 



That some individuals of M. flava sometimes remain behind in their winter 

 quarters is an interesting fact, though by no means an isolated one, and tends 

 to prove that migration is not the effect of a blind irresistable impulse driving 

 the bird on its alternate northward and southward journeys. 



221. MOTACILLA BOARULA L. 



Grey Wagtail. 

 Two subspecific forms of the Grey Wagtail have so far been distinguished: 



4- 1. The typical Motacilla boarula. 



a. Motacilla boarula (1) Linn., Mant. Plant. 1771, 527; (11) Gould, B. Eur. 1837, 11, pi. 147. 



b. Motacilla sulphurea (1) Bechst., Natiu-g. Deutschl. 1807, m, 459; (11) Naum., Vog. 



Deutschl. m, 824, t. 87 (1823); [3) Newton, ed. Yarr. Br. B. 1873, I, 552; (4) 

 Seeb., Br. B. n, 1884, 203, pt. 



