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. — Diurnal Family. 



With the eyes and ears of moderate size. The plumage close and 

 compact ; and with the middle toe-nail like the rest. 



SWALLOWS. (HiRUNDO. Linn.) 



In these birds the bill is short, triangular, depressed, wide at 

 its base, and cleft nearly to the eyes ; the upper mandible notched 



