CYPSELID^ — THE SWIFTS. 421 



Family CYPSELIDiE. — The Swifts. 



Char. Bill very small, without notch, triangular, much broader than high ; the culmen 

 not one sixth the gape. Anterior toes cleft to the base, each with three joints, (in the 

 typical species,) and covered with skin or feathers ; the middle claw without any serrations ; 

 the lateral toes nearly equal to the middle. Bill without bristles, but with minute feathers 

 extending along the under margin of the nostrils. Tail-feathers ten. Nostrils elongated, 

 superior, and very close together. Plumage compact. Primaries ten, elongated, falcate. 



The Cypsdida;, or Swifts, are Swallow-like birds, generally of rather dull 

 plumage and medium size. They were formerly associated with the true 

 Swallows on account of their small, deeply cleft bill, wide gape, short feet, 

 and long wings, but are very different in all the essentials of structure, 

 belonging, indeed, to a different order or suborder. The bill is much smaller 

 and shorter ; the edges greatly inflected ; the nostrils superior, instead of 

 lateral, and without bristles. The wing is more falcate, with ten primaries 

 instead of nine. The tail has ten feathers instead of twelve. The feet are 

 weaker, without distinct scutellse ; the hind toe is more or less versatile, the 

 anterior toes frequently lack the normal number of joints, and there are 

 other features which clearly justify the wide separation here given, especially 

 the difference in the vocal organs. Strange as the statement may be, their 

 nearest relatives are the Trochilidm, or Humming-Birds, notwithstanding 

 the bills of the two are as opposite in shape as can readily be conceived. 

 The sternum of the Cypsdidm is also very different from that of the Hirun- 

 dinidce, as will be shown by the accompanying figure. There are no emargi- 



Ch^etura ptlagica. Progne subis. 



nations or openings in the posterior edge, which is regularly curved. The 

 keel rises high, for the attachment of the powerful pectoral muscles. The 

 manubrium is almost entirely wanting. 



In this family, as in the Caprimulgidce, we find deviations in certain 

 forms from the normal number of phalanges to the toes, which serve to 

 divide it into two sections. In one, the Chmturina', these are 2, 3, 4, and 5, as 



