2o6 CALIFORNIA ACADEMY OF SCIENCES. 



vicinity. There were fluctuations in abundance that may 

 have been due not to shifting of fishing grounds, but to 

 departure of adult birds and arrival of others later from 

 further north. 



The peculiar features of migration in August, as com- 

 pared with July, were the larger number of birds that 

 temporarily halted by the way, the greatly increased size 

 and frequency of the waves, and the greater prominence 

 of boreal species. 



The additional northern birds to arrive were the Red 

 Phalarope, Surf Bird, Parasitic Jaeger, and Pacific Ful- 

 mar (dark phase), during the first half of the month, and 

 the Arctic Tern, Long-tailed Jaeger, and Sabine's Gull, 

 during the second half. 



Conspicuous migratory waves were observed in the 

 following species: — 



Dark-bodied Shearwater, on the ist and 2d, the wave 

 beginning July 31st and reaching its height on the ist; 

 on the 6th and 7th; on the nth and 13th, the height of 

 the wave perhaps occurring on Sunday, the 12th; from 

 the 20th to the 23d, the height being reached on the 22d; 

 on the 27th. 



Marbled Murrelet, on the ist and 2d — the aftermath of 

 the wave of the closing days of July; on the 14th, man- 

 ifested solely by the presence of the birds on the water. 



Northern Phalarope, from the 3d to the 7th, the height 

 being on the 6th; on the 13th; on the 20th; on the 23d 

 and 24th; on the 27th. 



California Murre, from the 3d to the 7th ; from the nth 

 to the 13th, the height probably being attained on the 

 1 2th, Sunday; from the 17th to the 20th, the height ap- 

 parently being on the 20th. 



Cassin's Auklet, on the 6th and 7th, manifested solely 

 by birds on the water; on the 23d. 



