54 THE VICTORIAN NATURALIST. 



species inhabits the western portion of the continent, no repre- 

 sentative having yet been recognized in the intervening space, 

 where few reed-beds exist. 



With this brief allusion to my inclusion of these three doubtfuls, 

 from an anatomist's point of view, in my field observations I will 

 at once proceed to that most familiar of hedge birds, the Yellow- 

 rumped Geobasileus, Geobasileus chrysorrhcea, Q. and G. This little 

 tit or so-called " yellow-tail," to city people the most familiar of 

 country native birds, is of a small size and even appears to attract 

 more notice than the Ground Lark or proper Pipit. Thechrome-yellow 

 of the upper tail coverts, with apex of each rectrice barred with 

 black, makes this little grey bird a distinctly prominent one. The 

 markings are only noticeable when the birds, finding themselves 

 disturbed on the feeding ground, rise upon wing and with blended 

 voices alight in the acacia. They quickly return to the grass and 

 appear to have little fear of man. With the aid of their tiny feet 

 the birds move rapidly along the ground in search of insects. 



This one of ten species of a genus peculiar to Australia puts 

 aside its gregarious habit about July, and enters upon the work of 

 nest-building, a structure that is generally placed within nine feet 

 or rarely over twelve feet from the ground. The house is one- 

 chambered, dome-shaped, and with cuplike cavity fitted to each 

 above for the non-sitting bird, when the shades of night have 

 fallen and the food of this species has retired. Occasionally two 

 chambers will be formed, without an upper cavity, one lined with 

 care, the other not so, and no dependence can be placed upon 

 which will be correctly finished. 



I believe the cuckoo's actions will finally settle the matter, for 

 if the " parasite's " egg be deposited in one cavity before laying of 

 eggs of the rightful owner, the Geobasileus will place its eggs in 

 the other, with the result that the cuckoo will not be hatched. 



In the case where a one-chambered nest has become utilized 

 by the stranger, the " tit " may cover the introduced coloured egg 

 with a lining of feathers, and so prevent incubation ; but this is 

 not generally resorted to, and the strongest chick becomes the 

 sole surviving member of the group. At another time the cuckoo 

 may be " unfortunate " in the deposition of its egg within the 

 cup-shaped cavity of the nest, after which it will naturally remain 

 unhatched, but this is of rare occurrence. 



Last season I observed a double nest — a semi-detached house 

 — built in the whin, both perfect externally, but the inner one 

 with its entrance facing the bush — an unusual position — finished 

 internally. The whole was new, and the outer one contained an 

 egg of the Narrow-billed Bronze Cuckoo, the inner a clutch of 

 the Geobasileus. The birds appeared to be in excellent plumage, 

 and were probably old enough to remember the disappointment 

 of c-ne or two past seasons, in so much as related to the hardship 



