94 SYSTEMATIC REVISION OF THE AUSTRALIAN THORNBILLS 
Acanthiza pusilla jayi Mathews, Aust. Av. Rec., ii, 1914, p. 98; Mac- 
donnel Ranges, Central Australia. 
Acanthiza pusilla peroni Mathews, Bull. Brit. Ornith. Club, xxix, 1918, 
p. 23; Peron Peninsula, Western Australia. 
Acanthiza pusilla nullahorensis H. L. White, Emu, xxi, 1922, p. 164; 
Zanthus, Western Australia. 
Acanthiza apicalis ererna A. G. Campbell, Emu, xxii, 1922, p. 64; 
Kychering, South Australia. 
Acanthiza pusilla dundasi Mathews, Birds of Aust., ix, 1922, p. 431; 
Lake Dundas, Western Australia. 
Range . — Interior of the continent from south-western Queensland and 
extreme western New South Wales, west to coastal mid-western Australia; 
to Tanami in the north and Eyre Peninsula in the south. 
Specimens Examined. — Forty-nine from the following localities: Central 
Australia: Powell’s Creek, Hermannsburgh, Mission Plain, Palm Valley. 
South Australia : Everard Ranges, Moorilyanna, McDouall Peak, Lake 
Gairdner, Gawler Ranges, Port Broughton, Iron Knob, Nonning, Mt. Hope, 
Wilcherry, Coffin’s Bay Peninsula, Kychering (type of A. apicalis erema ), 
Ooldea. Western Australia: Naretha (type of nullarborensis ) , Zanthus, 
Kalgoorlie, Lake Way, Yalgoo, Shark Bay, Peron Peninsula, Sullivan’s 
Creek, Ebano, Yandanooka, Morewa. 
Measurements. — Forty-five adult specimens of both sexes: wing, 48-55 
(5L9); tail, 42-50 (45.4); exposed oilmen, 8 5-10 (9); tarsus, 18-20 
(18-8). 
Subspecific Characters . — Much paler than all other races of pusilla. General 
colour above light greyish olive; upper tail-coverts snuff brown, and this 
colour does not extend on to outer margins of tail feathers; lower ventral 
surface white, faintly tinged pinkish buff on flanks and under tail-coverts ; 
feathers of forehead blackish brown with light, almost white, subterminal 
bands as in albivcntris with which this race agrees in depth of tail-band and 
extent of white on inner webs of lateral tail feathers. 
If consideration liad been given to the general similarity of 
environmental conditions throughout the interior of Australia 
the synonymy of this form would not be so extensive. It would 
appear that even Mathews has realized the uselessness of most 
of the above names for he has since consigned six of them, 
including five of his own, to synonymy, although in so doing 
no proper understanding is shown of faunal areas in Australia 
(Syst. Av. Aust., p. 603). 
In the series examined individual variation is apparent. 
Most birds from Eyre Peninsula, in the south, are slightly 
darker, deeper grey above and more huffy on the flanks, but 
these can be matched by occasional specimens from central and 
mid-west Australia. Three examples from the extreme south- 
east of Eyre Peninsula have the upper parts more brownish 
and the upper tail-coverts tinged reddish brown, thus 
approaching cdbiventris and it is possible that more material 
may prove the presence of that race in the extreme south of 
