Genus CYPSELUS, Ihe. 
Gen. Cuar. Beak very short, triangular, large, all its base concealed, depressed; gape ex- 
tending beyond the eyes; upper mandible hooked at the point; nostri/s longitudinal, near 
the ridge of the beak, open, the edges raised and furnished with small feathers. Tarse 
very short. Toes four, all directed forwards and entirely divided; nazls short, strong 
and hooked. Taz/ composed of ten feathers. Wings very long; the first quell-feather a 
little shorter than the second. 
SWIFT. 
Cypselus murarius, Temm. 
Le Martinet. 
We know of no birds, and certainly none in Europe, possessed of equal power of flight with the species of 
the present genus: in fact, their natural habitat appears to be the air, their short feet and strong claws serving 
more especially to cling to the rough surface of rocks, towers, and high buildings, or firmly securing them 
while in a state of repose. Their extraordinary length of wing, combined with the shortness of their tarsi, 
prevents them walking on, or rising from, any level situation, unless by repeated exertions, or taking advan- 
tage of some slight elevation; they are therefore seldom, if ever, to be seen on the ground. These birds are 
distinguished not only by the velocity of their flight, but by the smooth and graceful sweeps they take during 
their aérial career in pursuit of the various insects constituting their food. In fine and serene weather, when 
these insect tribes ascend to an almost incredible elevation, the Swifts occupy the highest regions of the atmo- 
sphere, persevering in the chase almost beyond the reach of sight. Their degree of elevation, however, 
doubtless depends on that of the insects, and the latter on the influence of the weather; so that the low or 
high flight of these birds may be taken as a barometrical index of the state of the air, and the consequent pro- 
bability of rai or the contrary. 
The Swift, which is spread over Europe generally, is essentially migratory. It arrives in England at the 
beginning of May, and leaves us again as early as August or September. It breeds in old buildings, steeples, 
ruins, towers, and rocks. The eggs are white. 
The colour of the plumage, with the exception of the throat, which is white, is of a uniform sooty-black 
with bronze-coloured reflections. The sexes offer no external marks of distinction. 
WHITE-BELLIED SWIFT. 
Cypselus alpinus, Zemm. 
Le Martinet a ventre blanc. 
Tue claims of this fine Swift to a place in the Fauna of Great Britain rest on the circumstance of one noticed 
by Mr. Selby in the ‘‘ Transactions of the Northumberland, Newcastle, and Durham Natural History Society ;” 
and one we have personally inspected, which was killed by the gardener of R. Holford, Esq., on his estate 
at Kingsgate near Margate, in whose possession it now remains. 
The natural habitat of the Cypselus alpinus is more exclusively limited to the middle of the southern dis- 
tricts of Europe, particularly its alpine regions, and the shores of the Mediterranean, being very abundant at 
Gibraltar, Sardinia, Malta, and throughout the whole of the Archipelago; and to these may also be added the 
northern parts of Africa. In its manners it closely resembles our well-known Swift, but possesses, if possible, 
still greater powers of flight. 
It would appear that the clefts of rocks and high buildings are the sites which this bird chooses for the 
purpose of nidification ; the female laying three or four eggs of a uniform ivory white. 
The sexes of this species present but little differences, the colour of the female being rather less decided ; 
in the male a uniform greyish brown is spread over the whole of the upper surface, which descends across the 
breast in the form of a band, along the flanks and over the inferior tail-coverts ; the throat and the middle of 
the belly are of a pure white, the tarsi covered with brown feathers, and the irides brown. Length from 
nine to ten inches. 
