BIRDS OF MINNESOTA. 355 



nesting habits of this beautiful swallow which has been noticed 

 so much of late years, I believe to have been associated with 

 its entire history, and is abundantly verified here. 



SPECIFIC CHARACTERS. 



Glossy metallic green above; entirely white beneath; nos- 

 trils basal, small, oblong, and covered by a membrane; tail 

 emarginate; tarsus naked and shorter than the middle toe, and 

 scutellate. 



Length, 6.25; wing, 5; tail, 2.65. 



Habitat, North America at large. 



CLIVICOLA RIPARIA (L.). (616.) 

 BANK SWALLOW. 



This smallest of the swallows, which avoids all intercourse 

 with man, seeking its breeding places in the neighborhood of 

 streams and lakes, often quite inaccessible, would be a hard 

 species to watch as to the times of their arrival and departure 

 but for the circumstance of their spending their nights in their 

 holes in the banks where they breed. When new holes have to 

 be excavated, it is done very rapidly, so as to provide a place 

 for the first night's lodging. An early visit to the vicinity of 

 the banks will determine their arrival. A single locality may 

 be occupied by only a few birds, but many places within a short 

 distance of each other are occupied by hundreds, if not thou- 

 sands. The supply of food must in some measure determine 

 that, although the possibilities of their wings may meet most 

 emergencies of that kind. 



They reach the greater part of the State by the 5th of May as 

 a general thing, and at once enter upon their nidification. The 

 nest is usually at the end of a hole about half a yard in length, 

 and consists of a cavity of sufficient dimensions to receive an 

 ample quantity of dried grasses, hay, feathers and down of 

 different kinds. Sometimes the nest is much further in the 

 bank. 



They deposit four or five pure white eggs, and bring out two 

 broods in due time for the last to be ready for the southern 

 migration by the 25th of August. 



Its nidification habits doubtless restrict its numbers in certain 

 districts, but it is an abundant species. I have not failed to 

 find it in every important section seen or heard from. 



SPECIFIC CHARACTERS. 



Smallest American swallow. Tail slightly emarginate, outer 

 web of first primary soft, without hooks; lower part of tarsus 



