188 HIRUNDIN1D.E. 



length, from the beak to the end of the tail, about eight 

 inches and a half; and from the beak to the extremity of 

 the wings ten inches. Wing, from the carpus to the tip, 

 eight inches and seven-eighths. The beak measures four 

 lines from the forehead to the tip, and full ten lines from 

 the tip to the gape. 



The entire plumage of this bird is dusky, with exception 

 of the chin, throat, and belly ; the dusky band which crosses 

 the breast is rather deeper in colour than the rest of the 

 plumage, and the forehead and top of the head are tinged 

 with grey. The whole feathering of the bird is of a very 

 silky texture. The beak is black ; the iris dusky. 



In this species, as in the Common Swift, the principal 

 length of the wing consists in the prolongation of the primary 

 quill-feathers, which, together with the extreme shortness of 

 the secondary and tertial feathers, gives that peculiarity of 

 appearance which enables the most superficial observer to 

 distinguish the Swift from all other birds when on the wing. 



The outline head, fig. 37, is that of the Alpine Swift. 



Figs. 36, represent the head of the Common Swift (c. 

 murarius) in two points of view, all are of the natural size. 



