58 PASSERES. 



Sub-Tribe IT. 



DIURNAL FISSIROSTRES. FISSIROSTRES DIURNL 



The Fissirostral birds that fly by day are at once distinguish- 

 able from the nocturnal species by the closeness of their plumage, 

 which is quite devoid of that fleecy appearance so eminently 

 characteristic of the preceding tribe. 



FAMILY I. 

 THE SWALLOWS. IIIRUNDINID/E. 



General Characteristics. — Bill short and weak, very broad at the base, and sud- 

 denly compressed towards the tip ; the wings are long, narrow, and pointed ; the 

 tail forked ; and the tarsi very short and feeble. This group comprises the Swifts 

 and the Swallows. 



These birds are rem.arkable for their powers of flight and in- 

 sectivorous appetite. Their legs are short and comparatively 

 feeble ; but the toes are furnished with sharp hooked claws, con- 

 structed for the purpose of clinging to walls or the sides of rocks. 

 In the swifts the toes are all directed forwards; in the true swallows 

 the hind toe is reversible. The wings are long and pointed, and 

 the quill-feathers of a firm texture ; the general plumage is close- 

 set, smooth, sometimes polished and glossy. The beak is small, 

 depressed, broad at the base, and with a wide gape. Their food, 

 consisting of the smaller species of insects, is always taken on the 

 wing, and they often completely fill their throat with insect prey, 

 so as to distend it like a pouch, doubtless in order that their nest- 

 lings may have a full supply at each visit. The whole of the active 

 existence of these birds is passed in the air. They skim along with 

 marvellous rapidity, and quarter their ground over meadows, lakes, 

 and rivers, wheel round barns and steeples, and dash along appa- 

 rently as untired when evening closes as when they began their 

 aerial exercise with the first dawn of day. They feed and drink 

 on the wing, and pursue each other in sportive chase, performing 

 the most rapid and beautiful evolutions. 



The swallow tribes manifest a decided predilection for the neigh- 

 bourhood of water and those situations in which insects most 

 abound ; of these they destroy incalculable numbers, and thus rid 



