Ki:V T<> THK ]ilK!'- OP EASTERN \'>KTH AMKKir\. 



Section 4. Length, over 21 ; bill, under 2; underparts, 



not white. 



<mter weh- ot primaries dark lirowu: hill, overl.'.K) (immature,). 



Larus aryentatus smithsonianus. American Herring Gull. 



See No. 30. 



Outer \vt-li-! <>f primarir-. hrownisli ; lill, undt-r !.!>() (/miniature). 



iis l.-iintlii i>i. Kumlien's (lull. 

 Sec No. i'<;. 



< >ulT \\ c-l of pri marie-, a-li i-iil>r (immature i. 



x. Iceland (iull. 



See \o. -25. 



Section 5. Length, under 21. 



A kind <>t' lilai-k on the I. ill .adult I. Hill, dull yellow, tipped with Mack fnnmatiire\ 



Larus delawarensis. Ring^billed (iull. 

 SIM- No. 31. 



" 

 ' 









Gulls. 



Group 5. Wing, over 17 inches long. 



lYimarie-. marked with more <>r le-< l.laek. Lama ni<ti-in HH. (ireat Black-backed (iull. 



See \. -J7. 



N" l>l:ieK on primaries. I.-U-HX iil'iiii-nn. (ilaucous (iull. 



See No. 34. 



i "i direction! for measure ni, 



