Plate IV. Pages 86, 88. 



HERRING GULL. 



Length, 24-00 inches. Adult, back and wings pearl-gray; end of primaries 



marked with black; rest of plumage white. Young, dark grayish, primaries 

 and tail brownish black. 



PETRELS. 

 Length, 7-50 inches. Black, upper tail-coverts white. 



