BIG-BILLED THICKHEAD. 
Distribution. Northern Tropical Australia from Parry Harbour, North-west Australia, 
to Cape York, North Queensland. 
Adult male. Crown of head, nape, sides of face, rictal bristles, a band across the fore-neck, 
and sides of neck deep black ; entire back, upper tail-coverts, scapulars, and upper 
wing-coverts citron-yellow, the basal part of the upper wing-coverts black ; bastard- 
wing, primary-coverts, and first primary-quill uniform black ; flight-quills blackish 
fringed with grey on the outer webs and whitish on the margins of the inner ones ; 
tail-feathers blackish slightly paler at the tips ; chin, white with blackish hair-like 
tips to the feathers ; throat also white ; a band across the hind-neck, breast, sides 
of body, abdomen, thighs, and under tail-coverts buttercup-yellow ; axillaries and 
under wing-coverts white with a tinge of yellow ; under-surface of flight-quills 
hair-brown with buffy-white on the inner margins ; lower aspect of tail blackish- 
brown, paler on the margins of the feathers at the tip. Bill black ; eyes dark 
brown ; feet black. Total length 172 mm. ; culmen 13, wing 86, tail 67, tarsus 24. 
Figured. Collected at Borroloola, McArthur River, Northern Territory, on the 
23rd of June, 1913. And is the type of Pachyce'phala rohusta borroloola. 
Adult female. Crown of head and nape greyish-brown ; ear-coverts brown with pale shaft- 
streaks to the feathers ; hind-neck ochreous ; back, scapulars, and lesser upper 
wing-coverts dark yellowish-green ; rump and upper tail-coverts citron-yellow ; 
tail-feathers black fringed with citron-yellow at the base and dusky-brown at the 
tips ; median and greater upper wing-coverts blackish broadly margined with 
greenish-grey ; bastard- wing and primary-coverts slightly margined with greenish- 
grey ; flight-quills black fringed with grey on the outer and inner webs, more 
broadly on the inner secondaries ; rictal bristles black and directed forward ; 
lores whitish at the base, grey at the tip, and bristly in texture ; chin white, 
with black hair-like tips to the feathers ; throat also white with grey tips to 
the feathers ; a slightly indicated band of ochreous-buff across the fore-neck ; 
breast, abdomen, sides of body, and under tail-coverts buttercup-yellow ; axillaries 
and under wing-coverts white, outer edge of wing tinged with yellow ; under-surface 
of flight-quills hair-brown, whitish on the inner edges ; lower aspect of tail blackish- 
brown, paler at the tip. Bill black, eyes dark brown, feet grey. Total length 
172 mm. ; culmen 13, wing 87, tail 70, tarsus 23. Figured. Collected at the same 
place and date as the male. 
Immature. Back and scapulars olive-green with a few chestnut tipped feathers inter- 
mixed ; upper tail-coverts chestnut, the lateral ones pale buff ; upper wing-coverts 
and outer aspect of the wing rust-brown ; inner webs of flight quills blackish paler 
on the inner edges ; tail bronze-brown ; crown of head for the most part rust-brown 
with a patch of olive-green on the nape, many of the feathers on the middle of the 
crown and occiput still in sheaths and undeveloped ; lores grey ; rictal bristles black ; 
sides of the face and throat pale cinnamon-buff ; sides of breast olive-green ; middle 
of breast, abdomen, and sides of body ochreous-buff, becoming paler and silky in 
appearance on the vent and lower flanks ; under tail-coverts similar in colour to 
the throat ; axillaries and under wing-coverts pale cinnamon ; under-surface of 
flight-quills dark brown with buff inner edges ; lower aspect of tail bronze-brown 
with a yellowish tinge. Eyes black, feet pink, upper mandible brown, lower pink. 
Collected at Cape York, North Queensland, on the 30th of May, 1913. 
Immature male. Crown of head, back, scapulars, and upper wing-coverts olive with a 
tinge of yellow ; inner webs of the median and greater upper wing-coverts, bastard- 
wing, primary-co verts and flight-quills blackish with whitish inner margins to the 
last, outer edges of primary-quills hoary-grey, outer webs of inner secondaries rust 
colour ; upper tail-coverts greenish-yellow ; tail yellowish-green with dark shafts 
VOL. VIII. 
225 
