KKY TO THE BIRDS OF EASTERN NORTH AMKRICA. 



art-, \\hite; tir-i primary, entirely black or dark brown (adult). 



I.<irns utricillit. Laughing Gull. 

 See No. 33. 



-ral plumage, white : back, white j first primary entirely white, or with a MaekUh 

 -P--I at tip: hind toe, with nail; hill, yellow. r,nj<>i>1iil<t <iUm. Ivory Qull. 



See \o. -2-2. 



Hack. |>earl irray : inner \\e!> of primary, \\hite. broadly tipped with blark ; a small rudi- 

 mentary hind toe without nail. /,'/</ ///*/,/</,//,. Kittiwake Gull. 



See No. ::<. 



" Group 3. Wing, 13 to 15 inches long. 



I'nd.-rparts. white; first primary entirely blark, or dark brown. 



/.urns utrii-iiiii. Laughing Gull. 

 See Xo. :{;{. 



(ieneral plumage, white: tirst primary, entirely white, or with a dusky spot near tip; hind 

 toe. \\ iih nail : hill, less than 1 .."><); wing, less than 14; hill, yellow. 



Piif/itjihifii nU'ii. Ivory Qull. 

 See No. -2~2. 



T"n<lerparts, white; inner weh ot primary, white, broadly tipped with hlaek : a small 

 rudimentary hind toe. without nail. l.urn* tri<i<t<-ti/1,t. Kittiwake Gull. 



See No. 23. 



1 nderparts, white; terminal portion of first primary, black, with white spot near tip. 



Larnn <i,'liii-iir<'iixi*. Ringbilled Gull. 

 See No. 31. 



1'rimarie-. pale pearl gray, becoming white at tip ; hill, over l.")0: wing, over 14. 



Isinis li'iti'u/tti-riis. Iceland Gull. 

 See No. -25. 



* Group 4. Wing, 15 to 17 inches long. 

 Section 1. Length, over 21 ; bill, over 2; underparts, white. 



No hlark on primaries ( ;idulti. La ft is iilmn-ns. Glaucous Gull. 



See No. i>4. 



I'.aek. -l.ity Mark: primaries, hlark with more, or less white (adult). 



/,<////> nun-ill us. (ireat Black-backed Gull. 



See No. -11. 



Hark, pale Miiish. <;ray, or pearl jrray : primaries, dull hlark or hrou ni-h black, more 

 or !" marked with while. 



Larus argentattw smfthaonianus. American Herring Gull. 



Sec No. HO. 



Fur ilirertionn for iiir:i.-iiri-iiu-nt, -<-c page !. 



