Vol. XVII. 

 1917 



"1 Correspondence. 113 



possibly winter together in New Guinea, does not affect the 

 question, as the authors appear to suppose. It has been known 

 for some years that two sub-species of Wheatear occur regularly 

 in England on migration in spring and autumn. The smaller 

 form remains to breed in the British Isles, while the larger passes 

 on to Scandinavia. A similar phenomenon is met with in the 

 cases of the Willow-Wren and the Chiffchaff. The sub-species 

 Phylloscof)its trochilits trochilits and Phylloscopus collybita collybita 

 remain in England- all through the summer, and are two of the 

 best-known British birds, but in spring and autumn some 

 individuals of the northern forms, P. trochiliis eversmanni and P. 

 collybita tristis, pass through England on migration. I have just 

 received a reprint of an article by my brother, H. G. Alexander, 

 from British Birds (vol. x., p. 263, April, 1917), in which he 

 records that Miss E. L. Turner and he watched specimens of the 

 Common and the Northern Willow-Wrens in company in the 

 same bushes at Dungeness on 13th September, 1916, and were 

 able to distinguish them both by their slightly different coloration 

 and their decidedly different notes. The European cases quoted 

 seem to me exactly comparable with the Australian cases referred 

 to by Messrs. Campbell and Barnard. In each we have sub- 

 species with different ranges in the summer mingling together 

 on migration, and in neither case are we aware whether the two 

 forms remain mixed during the winter or have distinct winter 

 areas. The fact, however, that they follow the same routes on 

 migration has not prevented European students from regarding 

 the birds mentioned as sub-species. — Yours, &c., 



W^ B. ALEXANDER. 



Queen's College, University of Melbourne, 17/7/17. 



To the Editors of " The Emu." 



Dear Sirs, — I beg to amend the classification at the end of 

 my article in the January, 1917, issue, p. 170. I had overlooked 

 the fact that Mathews, in the same volume (July, 1916, p. 34), 

 had separated Acanthiza albiventris from A. pusilla, adding A. 

 venus, A. hamiltoni, A. consobrina, A. whitlocki, and A. tanami 

 as sub-species, and leaving A. macularia, A. archibaldi, A. 

 diemenensis, A. zietzi, A. arno, A. apicalis, and A. katheriha as 

 sub-species of A. pusilla. 



Perhaps Mr. Mathews is correct, but the only difference, 

 according to the late Mr. A. J. North, is the white under tail 

 coverts and slightly larger size of A. albiventris. If this is 

 sufficient to separate A . albiventris specifically from A . pusilla, 

 it is strange that the under tail coverts in A. hamiltoni are 

 fulvous, as is also the case in A. pusilla and all, or nearly all, of 

 its sub-species. — Yours faithfully, 



F. E. HOWE. 

 Canterbury (Vic). 24/7/17. 



