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A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



Great Lakes, and in Europe south to Mediterranean, the Atlantic 

 islands from Madeira to Azores, and Cape Verde Islands, Senegal, and 

 Caspian Sea. Replaced by R. t. pollicaris on coasts of north Pacific, 

 Bering Sea and adjacent ocean, south to Commander and Aleutian 

 Islands, in winter south to California. 



Genus PAGOPHILA Kaup 



Pagophila Kaup, Skizz. Entw.-Gesch. & Natiirl. Syst. Eur. Thierw., 

 pp. 69, 196 (1829 — Monotype : Larus eburneus). 



Generally much like Larus. Adults quite white in summer and 

 winter. Tarsus not quite as long as middle toe with claw. Tibia 

 feathered almost to joint, while in Larus a conspicuous portion of 

 lower tibia is bare. Tarsi and feet very rough, back of tarsus not 

 distinctly reticulate but with callous rugosities in cross-rows. One 

 species. 



PAGOPHILA EBURNEA 



460. Pagophila eburnea (Phipps)— THE IVORY-GULL. 



Larus Eburneus Phipps, Voy. N. Pole, App., p. 187 (1774 — Coast of 



Spitsbergen). 



? Larus albus Gunnerus, Leem, Beskr. Finn. Lapp., p. 285 (1767 — 



N. Norway). 



Pagophila eburnea (Phipps), Yarrell, III, p. 656 ; Saunders, p. 685. 



Description. — Adult male and female. Winter and summer. — 

 Whole plumage pure white with shafts of primaries pale straw- 

 colour. Plumage acquired by complete moult June (sometimes 

 May) to Oct., and by moult confined to body in Feb. (only one in 

 spring-moult (Feb.) examined). 



Nestling. — Closely covered with longish down with fine hair- 

 like tips. Lips of down white, bases ashy blue-grey giving general 

 appearance of pale ash-grey. No pattern or markings. 



Juvenile. — Fore-head and lores dark lead-grey mottled white, 

 feathers being narrowly fringed white, more uniform dark lead- 

 grey round eye ; rest of 

 head, chin and throat white, 

 feathers with subterminal 

 dark lead -grey mottlings or 

 patches ; rest of upper- 

 parts white, varying num- 

 ber of feathers on back of 

 neck and upper - mantle, 

 scapulars and longer upper 

 tail-coverts with spot-like 

 subterminal brown-black marks ; rest of under-parts white with 

 some subterminal brown-black marks on flanks and often a few here 

 and there on breast ; axillaries white ; under wing -coverts mostly 



Juvenile Ivory-Gull (Pago2^hila fburnea). 



