64 cypseliDj*. 
contrary. They are occasionally seen near Gibraltar, and are 
said to arrive at Tangier somewhat earlier than the common 
Swift, though I could see no diflference in the time of their 
arrival. Easily noticed on the wing by their light colour, 
they mix both with the common and White-bellied Swifts. 
In May 1874, when near Vejer with two ornithologizing 
friends, we found this species to be more abundant than C. 
apus, while, curiously enough, at Algeciraz (where, as men- 
tioned, there are countless swarms of common Swifts) I never 
could detect one single C. pallidus. 
The general colour of C. pallidus is a uniform grey brown, 
except the throat, which is white, as are the tips of the feathers 
of the lower part of the breast, giving it a mottled appear- 
ance. 
48. Cypselus melba, Linn. White-bellied Swift, Alpine 
Swift. 
Moorish. El namera. Spanish. Avion. 
'' Found near Tangier on passage, crossing the Straits from 
March to May, returning from August to October. It is not 
so common as C. apus." — Favier. 
The White-bellied Swift breeds sparingly at Gibraltar in 
the inaccessible crevices of the rocks on the Mediterranean 
side ; they seem to arrive, if any thing, a little later than the 
common Swift. The earliest date of arrival noticed was the 
24th of March : many were seen on the 29th. On the 4th 
of April, 1871, near San Roque, I noticed a flock of about 
two hundred passing in a northerly direction, with a gyrating 
flight, making a great noise, though they were very high up. 
A few common Swifts (their cry attracted my attention to 
them) were with the flock. On the 5th of November, 1871, 
at Casa Vieja, I saw six hawking about over the marshes for 
about an hour, when they disappeared in a westerly direction. 
I fired several shots at them, but ineffectually, as they were 
too high. An ofiicer who was at Fez told me that he saw a 
great many Alpine Swifts there in large flights about the 23rd 
of February. 
The sexes are alike in plumage, except that the female 
