196 VISCOUNT WALDEN ON THE BIRDS 
MOTACILLIDZ. 
MoTACILLINA. 
Bupytss, Cuvier. 
114. BupyTEs virivIs. 
Green Wagtail, Brown, Ilustr. p. 86, pl. 33, “ Ceylon.” 
Motacilla viridis, Gm. S. N. 1. p. 962, no. 81 (1788), ex Brown; v. Martens, J. f. O. 1866, p. 10, 
no. 28, “ Manilla.” 
? Motacilla flava, ap. Kittlitz, Liitke, Voy. (Postels), iii. p. 327, “ Manilla” (1836). 
Observed by Dr. v. Martens at Manilla, both alive in the open country and preserved 
in the Military Library. 
CaLopates, Kaup. 
115. CALOBATES MELANOPE. 
Motacilla melanops, Pallas, Reisen Russischen Reichs, iii. p. 696, no. 16, “ Dauria” (1776) ; Zoogr, 
Rosso-Asiatica, i. p. 500, no. 135. 
Motacilla bistrigata, Raffles, Tr. Linn. Soe. xii. p. 312, “ Sumatra” (1821). 
Motacilla xanthochistus, Hodgs. Gray’s Zool. Misc. p. 83, “ Nipaul ” (1844). 
Pallenura javensis, Bp. Consp. i. p. 250, “ Java” (1850). 
Calobates sulphurea (Bechstein), Jerd. Birds of India, ii. p. 220, no. 592, ‘ All India and Ceylon.” 
Calobates melanope (Pallas), Swinh. P. Z. S. 1871, p. 364, no. 202, “China, Formosa, Hainan.” 
Hab. Luzon, January; Zebu, April (Meyer). 
Mr. Swinhoe (/. ¢.) has already remarked that the species of Calobates found in China, 
Formosa, and Hainan has a constantly. shorter tail than the European bird, and has 
separated it under the title given by Pallas to the species observed in Dauria. My own 
observations fully support Mr. Swinhoe’s conclusions, which apply to the Philip- 
pine bird also, as well as to all those I have examined from continental India. Although 
a small difference in the length of the tail is, by itself, a character too insignificant 
whereon to base a species, still it must be recollected that the lines of migration of the 
two forms are perfectly distinct, the short-tailed birds breeding in Northern Asia 
and visiting Southern Asia and its islands, those with the long tails breeding in 
Northern Europe and wintering in Southern Europe, Asia Minor, and Northern 
Africa’. Where the two races osculate remains an interesting point for future investi- 
gation ; and it is not impossible that the race which winters in Abyssinia will be found 
to breed in Siberia. 
‘ The great body of the migrants is referred to. Many individuals are known to halt and breed at inter- 
mediate points. 
