BANK SWALLOW 137 



tion of the species, for they have all been in 

 the second half of May, between May 18 

 and 30. On one occasion two birds were 

 present; on the other occasions a single 

 bird, either alone or with barn swallows. 

 They may be seen in their beautiful flight 

 passing back and forth in the air from one 

 end of the pond to the other, or again rising 

 higher in the air and measuring a larger 

 area of the Garden. 



62. Bank Swallow 



Riparia riparia 



Twice the presence of the Bank Swallow 

 has been recorded. On May 18, 1900, two 

 birds were noted, and on May 16, 1905, one 

 bird. On the first occasion they were in 

 company with barn and tree swallows. On 

 the second occurrence the single bird was 

 with barn and cliff swallows, one of a com- 

 posite flock of twenty birds moving cease- 

 lessly through the air and skimming the 

 waters of the pond. 



