THE BIRDS OF AUSTRALIA. 
P etrochelidon nigricans nigricans Mathews, Nov. Zool., Vol. XVIII., p. 301, Jan. 31st, 
1912. 
P etrochelidon nigricans australis Mathews, ib. 
P etrochelidon nigricans neglecta Mathews, ib. : North-west Australia (Fitzroy River). 
P etrochelidon nigricans distinguenda Mathews, ib. : East Murchison, West Australia. 
P etrochelidon nigricans rogersi Mathews, Austral Av. Rec., Vol. I., pt. 2, p. 38, April 2nd, 
1912 : Port Darwin, Northern Territory. 
Petrochelidon nigricans caleyi Mathews, ib., Vol. II., pts. 2-3, p. 65, Oct. 23rd, 1913 : 
Albury, New South Wales. 
Hylochelidon nigricans nigricans Mathews, List Birds Austr., p. 164, 1913. 
Hylochelidon nigricans caleyi Mathews, ib., p. 165 ; Belcher, Birds Geelong, p. 218, 1914. 
Hylochelidon nigricans rogersi Mathews, ib. 
Hylochelidon nigricans neglecta Mathews, ib. 
Hylochelidon nigricans distinguenda Mathews, ib. 
Distribution". Australia and Tasmania. [Extra-limital, Aru Islands and New Guinea.] 
Adult female. Crown of head, hind-neck, mantle, and upper hack glossy blue-black ; 
wings and tail dark brown ; rump and upper tail-coverts drab-grey ; fore-head 
pale rufous ; throat, breast, sides of body, and under tail-coverts isabelline with 
dark shaft-streaks to the feathers on the throat, fore-neck and breast ; abdomen 
white ; under wing-coverts and axillaries pale buff with dark markings on the 
margin of the wing ; under-surface of quills and lower aspect of tail pale brown. 
Bill black; iris brown; feet and tarsus blackish-brown. Total length 132 mm. ; 
culmen 6, wing 101, tail 50, tarsus 10. Figured. Collected at Marngle Creek, 
West Kimberley, North-west Australia, on the 31st May, 1911. 
Adult male. Similar to the above. 
Immature. Resemble the adult. 
Nest. A hole in a tree or cleft of a cliff. Lined with leaves or seaweed. 
Eggs. Clutch, four to five. Creamy or pearly-white. Sometimes found covered with 
specks of reddish-brown. 17 mm. to 18 by 13 to 14. 
Breeding-season. August to January or February. 
Gould, as usual, upon his first acquaintance with this bird, described it as a 
new species but in his “Handbook,” conformable to the Law of Priority, to 
which he was a strict adherent, he utilised the earliest name, that given by 
Vieillot many years before. 
As in the case of the other members of the family, much has been written 
about its nesting -habits, while there is not much on record of its life-history. 
Mr. T. P. Austin has written me from Cobbora, New South Wales : “ A 
very common species here during the latter part of the year, usually departing 
about the end of January, but sometimes a few birds remain throughout the 
whole twelve months. Before departing they will congregate in very large 
flocks. For several weeks about Christmas 1911 a very large flock gathered 
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