Pallas's Willow Warbler has recently been found almost every year during migration on the western slopes of the Ural range, but has only once been obtained on Heligoland, and once seen, though not secured; thus it is still an extremely rare straggler in Europe west of the Ural. The British-killed specimen was shot by a son-in-law of Mr. H.N. Pashley, who has obtained so many rarities at Cley-next-the Sea, where the last one procured was the Aquatic Warbler. Mr. Gätke holds that Pallas's Willow Warbler may be separated into two subspecies, the Siberian form, the true P. proregulus of Pallas, being greener and brighter in tinge of colour on the upper parts, the under parts being pure white with a lemon tinge, the second quill being equal to the eighth; whereas in the Himalayan or southern form, which he proposes ('Ibis,' 1889, p. 578) to call Phylloscopus newtoni, the second quill is equal to the tenth, the plumage is dull brownish yellow in tone of colour, and the under parts are not so white. I cannot, however, endorse this view, as in a series I have found both the tone of colour and the relative length of the quills very variable; but I may remark that, were it possible to recognize these two subspecies, the British-killed specimen must be referred, as might be expected, to the Siberian and not to the Himalayan form.
With regard to Phylloscopus viridanus, this Warbler has been obtained on Heligoland on three occasions. It inhabits Central Asia, but how far north it ranges I have not been able to ascertain. It is common in the Himalayas, and winters in India as far south as Ceylon. That it breeds in Europe there can be no doubt, as I received a young bird barely able to fly from Tjubuk, in the Southern Ural. This specimen I referred to Phylloscopus plumbeitarsus, Swinh., when in 1878 I wrote the article in the 'Birds of Europe,' but subsequently discovered and corrected my error.
