254 Mr. R. Swinhoe on Formosan Ornithology. 
15. Cypselus subfurcatus, Blyth. C. affinis, mihi, ‘Ibis/ 
1860, p. 48, et 1861, p. 30. 
This Swift is larger, much blacker, and with less furcate tail 
than its near ally, C. affinis , J. E. Gray, from continental India. 
Mr. Blyth has identified it as his Malayan species. It is locally 
distributed about South China, being generally resident in 
places where it occurs. It builds a nest under the eaves and 
rafters of houses much in the form of the House Martin ( Che - 
lidon urbica ), but the exterior coating of it differs in being 
composed of thin layers of wool, hair, and dried grass, glued 
one above the other with the saliva of the bird, and lined in¬ 
ternally with feathers. These nests serve the owners for a 
house all the winter through. In them they rear their young 
(only one brood in the year), in them they roost every night, and 
to them they frequently return during the day for rest after 
their long-sustained flights. The pairs keep together all the 
year, mingling however, in small parties, with others of the 
species from the same neighbourhood. These parties never 
seem to wander far, but seek their Dipterous food close to their 
homes, regulating the altitude of their flights according to 
the state of the atmosphere; and when a pair are anxious for 
rest, they leave the flock and fly down to their nests for repose, 
in which they remain twittering for half an hour at a time, and 
then dart out, pursuing and screaming after one another. In 
the spring they patch up the same nest, and use it as before 
till the close of the year. They seem to be very gentle birds, 
and greatly attached to one another. A pair built a nest under 
the beam of a verandah in my house at Amoy, and occupied 
the same for three years. I had thus ample opportunities of 
watching their habits. At Apes* Hill, Formosa, I met with 
this species again. Here it was nesting, not however under the 
roofs of houses, but in its primitive state under the ledges of 
rocks, building the same Martin-like nest. It was only in S.W. 
Formosa that I observed this bird; and I may here remark that 
I have never been able to trace it further north on the Chinese 
coast than Amoy, which is a trifle higher latitude than its posi¬ 
tion in Formosa. 
