1^8 Alhxandkr, TJie Whiie-winged Wrens. [ist^'oct 



articles, however, states clearly that he only regards the differences 

 between the two black-and-white island forms as entitling them 

 to sub-specific rank. He refers to the Blue-and-White Wren as 

 "the mainland representative" of the Black-and-White species, 

 and apparently quotes with approval Mr. Whitlock's view that 

 the two insular forms have evolved independently from the main- 

 land form. Now, it appears to me that if we accept this view 

 we must either regard the three forms as distinct species or as 

 geographical races (sub-species) of a single species. Mr. Mathews 

 considers the Black-and-White Wrens as entitled to generic 

 distinction, constituting the genus Nesomahirus, with one species 

 and two sub-species, whilst for the Blue-and-White Wren he also 

 creates a genus, Hallornis, again containing one species and two 

 sub-species (eastern and western). This implies that the two 

 island races are more nearly allied to each other than they are to 

 the mainland form ; but if the two island forms ha\'e been derived 

 independently from the mainland form, then they must each 

 be more nearly related to that form than they are to one 

 another. 



Now, on examination of the 23 adult males of Malunis cyaiiolns 

 referred to above, I find that they vary very considerably, some 

 Ix'ing quite bright blue and others dark ; moreover, most of the 

 darkest birds are from the most south-westerly part of the range 

 of the species — viz., the Wongan Hills and Yandanooka. Mr. 

 Milligan pointed this out in The Emu, vol. iii., p. 223. This seems 

 to me to lend strong support to Mr. Whitlock's theory, as a liird 

 from the Wongan Hills is almost exactly intermediate in colour 

 ])etween the lightest form of M. cyanotus and M. leiicoptcrus. 

 I have no specimens from the coastal district between Geraldton 

 and Dirk Hartog Island, but it seems just possible that specimens 

 approaching M. Icucopteriis even more closely may be found in 

 this little-known region in the future, though Mr. Carter found 

 the Blue-and-White Wren on the Edel-land Peninsula. 



In view of these facts, I think that both Blue-and-White and 

 Black-and-White forms should be regarded as geographical races 

 of a single species, and should be named — 



Maliirus h'licoplcriis leucoptcriis, Dirk Hartog Island. 

 cyanotus, Australia. 

 edoiiardi, Barrow Island. 



If they are entitled to generic rank the genus name would be 

 Hallornis instead of Malunis. 



I do not know of any quite similar instance among Inrds, tnit 

 the common kangaroo furnishes a close parallel, as we have 

 Macropus giganleus giganteus on the mainland and Macropus 

 giganteus fnliginosus in Tasmania and Kangaroo Island. I 

 believe that careful comparison would indicate sub-specific 

 differences between the two island races of kangaroo, in which 

 case the parallel would be exact ; but this is nut tlie lace to 

 discuss the question. 



