48 KEY TO THE BIRDS OF EASTERN NORTH AMERICA. 



* Group 3, Wing, 6.50 to 9.50 inches long. 



Upper parts, dark sooty brown or grayish black ; un- 

 derparts, white ; sides of breast, tinged with gray ; middle 

 toe and claw, less than 2 inches long. 



Puffinus auduboni. Audubon's Shearwater. 



See No. 62. 



The Manx Shearwater, Puffinus puffinus, a European 

 species, somewhat resembles Audubon's Shearwater, but it 

 is larger, the back darker, the wing rarely, if ever, measur- 

 ing less than 8.40 inches, and the middle toe and claw 2 inches or more. It is of accidental 

 occurrence on our coast. 



* Group 4. Wing, 11 to 13 inches "long. 



Upper and under tail coverts, gray or brownish gray ; breast, white. 



Puffinus major. Greater Shearwater. 



See No. 60. 

 Under tail coverts, gray; upper tail coverts, sooty; breast, gray. 



PuffimisfuWjinosus. Sooty Shearwater. 



See No. 63. 

 Upper and under tail coverts, white. ^Estrelata hasitata. BIack=capped Petrel. 



See No. 64. 



Upper tail coverts, pearl gray; under tail coverts, white, or entire plumage, dark slate 

 color (dark phase). Fulmarus glacialis, and races. Fulmar Petrel, 



See Nos. 57 and 58. 



* Group 5. Wing, 13 to 15 inches long. 



Upper surface of tail feathers, dark slaty brown ; under tail coverts, ash gray or brownish 

 gray. Puffinus major. Greater Shearwater. 



See No. 60. 



Upper surface of tail feathers, dark slaty brown ; under tail coverts, white, sometimes 

 slightly mottled with grayish. Puffinus borealis. Cory's Shearwater. 



See No. 59. 



Upper surface of tail feathers, pale pearl gray; upper tail coverts, pearl gray; under tail 

 coverts, white ; or entire plumage, dark slate color (dark phase). 



Fulmarus glacialis, and races. Fulmar Petrel. 

 See Nos. 57 and 58. 



* Group 6. Wing, 15 to 17 inches long. 



Upper surface of tail feathers, dark slaty brown; under tail coverts, ash gray, or 

 brownish gray. Puffinus major. Greater Shearwater. 



See No. 60. 



Tipper surface of tail feathers, dark slaty brown ; under tail coverts, white ; sometimes 

 slightly mottled with grayish. Puffinus borealis. Cory's Shearwater. 



See No. 59. 



* For directions for measurement, see page 9. 



