GAVI.K. 291 



287. LARUS MARINUS. 

 (GREAT BLACK-BACKED GULL.) 



Lams marimis, Linneus, Syst. Nat. i. p. 225 (1706). 



Tlie Great Black-backed Gulls of Yezzo and the Kuriles are appa- 

 rently identical with those found on the Commander Islands, and 

 named Larus sdiistisagus (Stejneger, Auk, 1884, p. 231). They 

 seem to intergrade with Larus marinus (of which they are doubtless 

 an Eastern race), and some examples from Japan are so absolutely 

 intermediate between the two forms that they may l)e referred to 

 either, and can only be recognized as Lariis marinus schistisayus. 



The Great Black-backed Gull is one of the largest species (wing 

 from carpal joint 20 to 18 inches). Its legs are flcsh-coluured, its 

 mantle very dark slate-grey, and the light pattern on the inner webs 

 of its primaries is obscure and seldom much cuueated. Its orbits are 

 vermilion. 



Mr. Snow obtained a scries of Gulls from the Kurile Islands, and 

 Mr. Whitely and Captain Blakiston have both procured specimens 

 near Hakodadi of a large size, and differing only from L. affinis in 

 having flesh-coloured instead of yellow legs and feet (Whitely, I])is, 

 1867, p. 210). There can be little doubt that they are identical Avith 

 the Gulls described by Dr. Stejneger as Larus schistisagus, which I 

 regard as the Eastern form of Larus marinus, and with which it 

 appears to intergrade. The Western race differs from the Eastern 

 one in being on an average a slightly larger bird, in having a some- 

 what darker mantle, and in possessing a white subterminal spot or 

 bar on the second primary. In the Swinhoe collection is a Gull 

 from Hakodadi (Swinhoe, Ibis, 1874, p. 165), which has a dark 

 mantle, but no subterminal spot on the second primary ; and in the 

 Pryer collection is an example from the Kurile Islands which has 

 the paler mantle, but possesses the subterminal spot on the second 

 primary. 



288. LARUS CACHINNANS. 



(PALLAS^S HERRING-GULL.) 



Larus caehinnans, Pallas, Zoogr. Rosso-Asiat. ii. p. 318 (1826)i 



Pallas's Herring-Gull is smaller than the Great Black-backed Gull 

 (wing from carpal joint 19 to 18 inches). Its legs are yellow, its 



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