MANUAL OF NATURAL HISTORY. 37 



1. Family. — Goatsuckers (Caprimulgidae). Bill 



very wide at base; margins of upper mandible 

 sometimes folding over lower, occasionally 

 provided with a tooth, short and compressed 

 at tip ; gape furnished with long stiff bristles. 

 Many have inner side of claw of middle toes 

 serrated. 



2. TRIBE. Diurnal Fissirostral Birds (Diurni). 

 Eyes smaller ; plumage compact. 



2. Family. — Swallows (Hirundinidae). Bill small, 



weak, very broad at base ; tarsi very short, 

 occasionally feathered ; sometimes all the toes 

 turned in front ; claws curved , wings very 

 long and pointed ; plumage more or less 

 glossy. 



3. Family. — Wood- Swallows (Artamidae). Bill 



stout, broad at base, more or less compressed 

 oilmen rounded, curved from base to the tip 

 nostrils round, pierced in substance of bill 

 upper mandible distinctly notched near tip 

 tarsi short, strong, covered with broad scales 

 toes rather long ; claws strong and com- 

 pressed ; wings long and pointed. 



4. Family. — Trogons (Trogonidae). Bill short, broad 



at base, narrowed and curved to tip, margins 

 serrated or notched near tip, base furnished 

 with bristles ; tarsi short, small, more or less 

 feathered ; toes two before, two behind ; plu- 

 mage very rich. 



5. Family. — Rollers (Coraciadidae). Bill broad at 



