532 
Bulletin of the British 
and Ch. sabinei has a much broader wing, and its under 
and upper tail-coverts are so much elongated as to 
cover the rectrices above and below, while in Ch. thomensis 
they leave nearly 2 cm. above and about 1 cm. below 
uncovered. 
Ch. thomensis is black above, including the wings and tail, 
with greenish and steel-blue reflections. Throat and breast 
dull greyish black, without gloss. Abdomen white, with dull 
black shaft-lines to the feathers. Upper and under tail- 
coverts white, with broad black shaft-streaks ; the longest 
upper tail-coverts almost entirely brownish black. Under wing- 
coverts black. Total length about 105 mm. (from tip of bill 
to end of tail), wing 116-117, tail 43, the bare tarso-meta- 
tarsus 8*5 mm. 
Three adult specimens were procured at Pedroma on the 
island of San Thome, W. Africa, by Mr. Albert Mocquerys. 
Mr. W. E. D. Scott exhibited a series of interesting 
photographs of the nests of the Spine-tailed Swift of North 
America ( Chcetura pelasgia), showing the growth of the 
nestlings at different periods of their advancement in age. 
He also gave some interesting details of the habits of the 
species. The photographs had been rendered possible by the 
removal of the sides of the chimney in his own house, so as 
to reveal the nests in situ. 
Mr. Scott also contributed the following notes on three 
new species of Tyrannidce from Patagonia, specimens of 
which he placed before the meeting :— 
“ The descriptions of these birds, apparently heretofore 
unknown, are based on material collected in Patagonia by 
Mr. J. B. Hatcher. Mr. Hatcher was sent on a scientific 
mission to this region by the University of Princeton, 
New Jersey, U.S.A. The study of the geology of the 
country and the collection of palaeontological specimens w r ere 
the chief objects of this expedition, but the collection of 
about one thousand birds clearly indicates that the existing 
fauna was in no way neglected. All of this ornithological 
