CTPSELID.E — THE SWIFTS. 



423 



the outside with feathers of various colors. As there is no shelf to receive 

 the eggs, it is believed that these are cemented against the sides of the 

 tube, and brooded on by the bird while in an upright position. Den- 

 drorhdidon kleclw, of Java, etc., builds a narrow flat platform on a horizon- 

 tal branch, of feathers, moss, etc., cemented together, and lays in it a single 

 egg. The nest is so small that the bird sits on the brunch and covers the 

 egg with the end of her belly. 



Owing to tlie almost incredible rapidity in flight of the Swifts, and the great 

 height in the air at which they usually keep themselves, the North American 

 species are, of all our land birds, the most difficult to procure, only flying 

 sufficiently near tlie surface of the ground to be reached by a gun in damp 

 weather, and then requiring great skill to shoot them. Their nests, too, 

 are generally sitiuited in inaccessible places, usually high perpendicular 

 or overhanging mountain-cliffs. Although our four species are sufficiently 

 abundant, and are frequently seen in flocks of thousands, it is only the com- 

 mon Chimney Swift that is to be met with at all regularly in museums. 



Subfamily CYPSELIN^. 



The essential character of this subfamily, as stated already, is to be found 

 in the feathered tarsus ; tlie reduction of the normal number of phalanges in 

 the middle toe from 4 to 3, and of the outer toe from 5 to 3, as well as 

 in the anterior or lateral position of the liind toe, not posterior. Of the 

 two genera assigned to it hy Dr. Sclater, one, Cijpsdus, is enlarged by him so 

 as to include the small West Indian Palm Swifts, Tadwrnis of Gosse. 



Genus PANYPTILA, Cabanis. 



PanypHla, Cabanis, Wiegni. Archir, 1847, i, 345. — Burmeistek, Thiere Bras. Vbgel, I, 



1856, 368. (Type, Rirundo cayanensis, Gm.) 

 Pscudoprocne, Streubel, Isis, 1848, 357. (Same type.) 



GrEX. Char. Tail half as long as the wings, moderately forked ; the feathers rather 



lanceolate, rounded at 



tip, the shafts stiffened, 



but not projecting. First 



primary shorter than the 



second. Tarsi, toes, and 



claws very thick and 



stout ; the former shorter 



than the middle toe and 



claw, which is rather 



longer than the lateral 



. , ,, , , Panyptila mdanoleuca. 



one ; middle claw longer 



than its digit. Hind toe very short ; half versatile, or inserted on the side of the tarsus. 



Tarsi and toes feathered to the claws, except on the under surfaces. 



