284 TIMELIID.B 



of the usual double structure, from which I flushed a bird on approaching it. The domed 

 portion was well lined with feathers and apparently just ready for laying in. On making a 

 further examination, I found an artfully concealed spout-Hke entrance leading to a second 

 domed chamber built underneath the other, and containing three young ones. I found a 

 similar structure at Enfield, near Sydney, on the 17th August, 1897, built in a Hakca acicularis, 

 the cup-shaped cavity at the top being unusually neatly made and the entrance to the upper 

 domed portion fairly conspicuous, while that of the under one was protected with a hood 

 and well hidden. The lower domed cavity contained four fresh eggs. Usually the nest is built 

 in the bushy end of a drooping branch, from three to six feet from the ground, but I saw one in 

 a dwarf gum built within ten inches of the ground, and have observed them as high as thirty 

 feet. Little or no preference is shown in the trees or shrubs selected as nesting-sites, but they 

 are frequently constructed in tea-trees, gums, pines, and needle-bushes; about orchards and 

 gardens prickly acacia, and other spine-covered hedge-plants, are chiefly resorted to as a 

 protection from nest marauding boys and other enemies. Probably the nest of no other species 

 stands so much in need of a protector; the fearless manner of the little owners in carrying 

 material for its construction often indicates the place in which it is built. Its bulky size, 

 too, when finished, generally renders it a conspicuous object, and it freriuently falls an 

 easy prey to the keen vision of bird-nesting boys. It is satisfactory to know, however, that 

 several broods are still reared every year within a short distance of the Sydney Post Office. 

 In common with several species, the Yellow-rumped Thorn-bill sometimes constructs its nest 

 underneath the nest of a Magpie, Whistling Eagle, or Wedge-tailed Eagle. Near Bathurst, 

 Mr. A. E. Ivatt informs me that he has found it underneath the nest of the Black-backed 

 Magpie. On the 2nd August, 1900, at a place known as "The Birthday," ninety miles north- 

 west of Port Augusta, South Australia, Dr. A. M. Morgan found a nest of the Wedge-tailed 

 Eagle, in a myall, containing two incubated eggs, and underneath it a nest of Gcobasikiis cliiy- 

 sorrhotis, but he did not examine the latter. At Port .\ugusta, twelve days later, he found a 

 nest of a Whistling Eagle in a dead gum, with three newly hatched young, and attached to the 

 sticks underneath a nest of Geobasileus chrysorrhotis containing three fresh eggs. 



The eggs are usually three, sometimes four in number for a sitting; their thin semi- 

 transparent shells, when fresh, rendering them of a pale flesh colour, but when blown they are 

 pure white. Occasionally sets are found with minute dots or flecks of pale red or reddish- 

 brown, sprinkled over the larger end of the egg, which in rare instances assume the form 

 of a more or less well defined zone. A set of three, taken at Ashfield, near Sydney, on the 8th 

 February, 1 891, measures:— Length (.\) 072 x 0-52 inches; (B) o-68 x 0-52 inches; (C) 071 x 

 0-51 inches. A set of four, taken at Enfield on the 17th August, 1S97, measures:— Length (.\) 

 071 x 0-5 inches; (B) o-68 x 0-4.9 inches; (C) 071 x 0-5 inches; (D) 07 x 0-5 inches. 



Fledgelings resemble the adults, but are duller in colour, the forehead is destitute of white 

 spots, and there is a distinct buffy tinge to the feathers of the fore-neck. 



In the neighbourhood of Sydney, the latter half of the year constitutes the usual breeding 

 season; but, with the exception of June, I have found nests with eggs, or young, throughout the 

 year. Nidification, in which both sexes take part, generally commences early in July, although 

 I have found half completed nests at Roseville on the ist of that month. A nest that I saw one 

 of these birds lining with feathers in the Sydney Domain on the 14th August, I was surprised 

 to find, ten days later, contained two incubated eggs on the point of hatching; another egg I 

 discovered under the lining at the bottom of the nest was quite fresh. If a nest is removed, 

 another is frequently built in the same situation. I took one from a pine at Ashfield, con- 

 taining three fresh eggs, on the 8th February, 1891; and on the 14th September of the 

 following year found another built in the same place, containing three young ones. 



This species is often the foster-parent of the Bronze C'uckoo (Lainprococcyx plagosusK 



