ORDER EIGHTH. 

SWALLOW TRIBE. (Chelidones. Vieill) 
With the bill very short, much depressed, and very 
wide at the base, the upper mandible curved at the point. 
Feet short and slender, 3 toes before, wholly divided, or 
united at the base by a short membrane, the hind toe 
often reversible ; the nails hooked. Wings very long 
and acute. 
The sexes and young nearly similar ; with the moult 
annual. These feed exclusively on insects, which they 
swallow flying ; they consequently migrate to tropical 
countries in winter. The flight is very rapid and long 
continued; (the diurnal section scarcely walk.) The 
vision very perfect ; and, according to their habits, diurnal 
or nocturnal. The voice in the proper Swallows is rather 
feeble and twittering ; in the nocturnal family quaint, 
singular, or monotonous. 
§ i. — D iurnal Family. 
With the eyes and ears of moderate size. The plumage close and 
compact ; and with the middle toe-nail like the rest. 
S W ALLO WS. ( Hirundo. Linn. ) 
In these birds the btll is short, triangular, depressed, wide at 
its base, and cleft nearly to the eyes ; the upper mandible notched 
