6)6. 



BANK SWALLOW. 



616. Riparia riparia. 5y inches. 



These are the smallest of our Swallows; this species 

 can be distinguished, even at a distance, by the con- 

 spicuous band across the breast, showing in bold relief 

 against the lighter throat. They are found throughout 

 North America, breeding from the middle of the U. 8. 

 north to the Arctic regions. 



They nest in colonies in holes in banks, laying the 

 four to seven white eggs on a grass nest in an enlarged 

 chamber at the end of the tunnel. 



BOUGH- WINGED SWALLOW. 



617. Stelgidopteryoc serripennis. 5% inches. 

 In this species the throat is gray as well as the breast. 

 The outer vane of the outer primary is stiff and bristly, 

 thus giving the species its name. These birds breed 

 from the Gulf north to Massachusetts and Washington, 

 in banks or in crevices of stone bridges. The eggs can- 

 not with certainty be distinguished from those of the 

 Bank Swallow, thev measure .75 x .52. 



130 



