586 BANK SWALLOW. 
seription given in the Fauna Boreali-Americana is a mere transcript of 
that which in itself is quite imperfect. Indeed, there is not in any work 
with which I am acquainted an account of the Sand Swallow, suffi- 
ciently minute and accurate to characterize in an adequate manner 
that very common species. 
The sociability and gentleness of these birds, the lightness and vi- 
gour with which they perform their various evolutions, the low and un- 
obtrusive twittering of their voice, in short, all their actions and eco- 
nomy, are delightful to contemplate. Their flight is exceedingly grace- 
ful, light, yet firm, and capable of great continuance. They seem indeed 
as if created for the purpose of spending their time on wing, for they alight 
less often to rest when full grown than any other of our species, when 
not sitting on their eggs, and are seen abroad searching for food later 
in the dusk, retiring for the night as late, I think, as our Swift, Oypse- 
lus Americanus. As they procure their food more commonly than the 
other species along the margins or over the surface of pools, lakes, ri- 
vers, or even the sea, their flight is generally performed at a small ele- 
vation, which is the case with others only when the wind blows smartly, 
or the atmosphere is damp and chill. The movements of their wings 
are those common to the family of Swallows, which flap these members 
less frequently than perhaps any other small land birds. The wings 
act on the hinge formed by the carpal joint, opening and closing like 
the blades of scissors. Their sailings, though frequent, are not exten- 
sive, and their tail appears to be of great service to them, as you ob- 
serve that on the least deviation from a straight course, it becomes 
suddenly more or less closed or inclined upward, downward, or side- 
ways; and when you see some hundreds of pairs about their breeding 
places, passing, repassing, and crossing each other in various ways, 
you almost wonder that they never come into collision with each other. 
The slightest movement in any direction seems sufficient to enable 
them to overtake and secure their prey ; and they less frequently than 
any other species follow an insect upward to any great distance. Like 
all other Swallows, they drink and bathe on wing. 
Their migrations are performed by day, although perhaps conti- 
nued by night, and their movements are more desultory and rather 
slower than those of other Swallows. It is rare to observe them in 
great flocks at that time, their associations not being apparently formed 
until they reach the countries in which they spend the winter months. 
