turned to the spot, and commenced a search for a nest, as a second bird had joined in the song. After a time I found a nest more like a Shrike-Thrush's than the neat but flimsy structure of a Thickhead. I imitated the notes of the singers, and brought them both to view. I could not recognise them. Hoping eventually to get eggs from the nest discovered, I did not disturb them further. About a mile further on I came across another bird like the specimen I had secured. It had no mate, so I shot it also. These birds were subsequently submitted to Mr. A. J. Campbell, who pronounces them to be immature examples of the Red-throated Whistler (P. rufogularis), a species I have not met with before. I made several visits to the nest I had found, and saw the owners at close quarters several times. The male had certainly no red throat. No eggs being laid, I took down the nest, which was in a small, dense clump of mistletoe of a very slender species. The nest had contained young. It was not like the ordinary type of Thickhead's nest. I did not disturb the parent birds in the hope they would nest again, but up to the time of leaving Naretha they had not done so. The identification of Thickheads is complicated by their often breeding before they have assumed fully adult plumage. I must assume, therefore, that this accounts for the absence of the red throat in the male under observation.
About a mile further on from the donga where I first observed the Rufous-throated Thickhead, I heard the song of another bird unfamiliar to me. I followed up the sound until I located the songster in a small tree. His mate was in a neighbouring tree. I watched for some time in the hopes they were nesting, but could see no evidence of this in their behaviour. I decided to shoot them both as I was so puzzled by their appearance and the unfamiliar notes. They were evidently a mated pair. I secured them, and on getting back to camp skinned and dissected both with extra care. The breeding organs of the male were in an advanced state, those of the female less so. With regard to plumage, the sexes are easily distinguishable; both are striped on the under parts, and have throats greyish white. The male has no trace of a black pectoral collar. The upper parts are ashy grey, without signs of immaturity in the shape of brown margins to the flight feathers. These two birds were also submitted to Mr. A. J. Campbell. He identifies them as the Rufous-breasted Whistler (Pachycephala rufiventris), the male in immature dress.
I am well acquainted with the latter species, and have found its nest and eggs in various localities further north. I am familiar, too, with its song, and had the male been singing like a male of P. rufiventris I think I should have at once recognised the songster. Immature males of the White-bellied Whistler (P. lanioides) sing in just the same manner as fully adult birds; the same applies to the Western Whistler (P. occidentalis), which nests near my house. The inference is that imma-
