MANUAL OF NATURAL HISTORY. 37 



1. FAMILY. Goatsuckers (Caprimulgidge). 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 (Artamidse). Bill 



stout, broad at base, more or less compressed ; 

 culmen 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 (Trogonidse). 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 (Coraciadidse). Bill broad at 



