CONTENTS. 
PAGE 
Genus GABIANUS 472 
No. 152. Pacific Gull, Gdbianus pacificus paciflcus . . . 474 
No. 153. Western Pacific Gull, Gabianus facificus georgii . 480 
Plate 121 lettered Gdbianus pad ficus, to face . . . 480 
Genus CATHARACTA 482 
No. 154. Australian Skua, Catharacta lonnbergi lonnbergi . 484 
Plate 122 lettered Megalestris antarctica, to face . . . 484 # 
Genus COPROTHERES 497 
No. 155. Siberian Pomarine Skua, Coprotheres pomarinus 
camtschatica . . . . . . . . . 498 
Plate 123 lettered Stercorarius pmnatorhinus, to face . . 498 - 
Genus STERCORARIUS 500 
No. 156. Arctic Skua, Stercorarius parasiticus . . . .501 
Plate 124 lettered Stercorarius crepidatus, to face . . 501 
