nC) PASSBRES. 



TRIBE J. 



FiSSIROSTRES.* 



The Fissirostral Passerine birds constitute a small, 

 but very natural group, distinguislied by the 

 structure of their beak, which is broad at the base, 

 short, hooked at the tip, and opening with a very 

 wide gape, extending to beneath, or even beyond, 

 the eyes, and thus adapted to catch and swallow 

 insects while on the wing. It comprises two prin- 

 cipal sections ; the first including those species that 

 fly by night, — Fissirostres Nodurni ; the other com- 

 prehending such as seek their food in the daytime, — 

 Fissirostres Diurni. The first of these sections 

 embraces the Groatsuckers, or Nightjars ; the second, 

 the extensive race of Swallows and Swifts. 



SUB-TBIBE L 



Fissirostres Nocturni. Nocturnal Fissirostres. 



The birds belono-ing' to this sub-tribe are re- 

 markable for the size of their eyes, which are very 

 large, and easily dazzled by the light of day, though 

 well fitted to descry objects in the obscurity of the 

 evening. Then' plumage is generally soft and fleecy, 

 like that of the Owls; thus enabling them to fly 

 without noise. 



FAMILY I. 



Caprimulgid.e. The Goatsuckers. 



Gen. Charac. — Bill short, depressed, very broad, gape extending beneath the 

 eyes ; toes long and rather strong, hind toe united to the base of the inner 

 toe. 



* Fissus, cleft, and rostrum, a beak ; Cleft-beaks. 



