53.2 Bulletin of the British 



and Ch. subiiwi has a much broadci- wing, and its under 

 and up|)er tail-coverts are so much eh)ngated as to 

 cover the rectrices above and below, vviiile in Cli. thomensis 

 they leave nearly 2 cm. above and about 1 cm. below 

 uncovered. 



Ch. thomensis is black above, including the wings and tail, 

 Avith 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 48, the baie tarso-meta- 

 tarsus 8"5 mm. 



Three adult specimens were procured at Pcdroma 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 

 Aniei'ica {Chcetura pelasgia), showing the growth of the 

 nestliLgs 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 Tyr'annidee 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 were 

 the chief objects of this expcdititm, but the collection of 

 about one thousand birds clearly indicates that the existing 

 fauna was in no way neglected. All of this ornithological 



