Capt. Sabine's Memoir on the Birds of Greenland, ^c. 543 



which were obtained, and which were very numerous, were all of 

 the latter plumage, which is certainly that of the perfect adult 

 bird. The white feathers on the forehead are found only on youno- 

 birds of the first year considerably advanced towards maturity. 

 In a still younger state it is supposed to be the S. obscura or Brown 

 'J ern of Gmelin and Latham, and perhaps also the S. nigra of the 

 Fauna Suecica, Miiller and Briinnich. There is a remarkable dif- 

 ference between the Greenland common Terns and those of the 

 European coasts, in their bills and legs ; the bills of the Greenland 

 birds are one-third shorter than the European ones, and the tarsi 

 of the former are only half the length of the latter. 



18. Larus Marin us. Great Black-backed Gull. 



L. TVlarimis. Fabr. 102. Temm. 490. 



Mature. L. Marinus. Gmel. i. 598. Lath. Lid. Oin. ii. 813. Bruii. no. 145. 

 Faun. Suec. 55. Miill. no. l63. — Black-backed Gull. Lath. Si/n. \a. 371. Br. 

 Zool. ii. 172. Arct. Zool. ii. 527.— Great Black-backed Gull. Mont. Diet. Sf App. 



Immature. L. Nsevius. Gmel. i. 598.— Wagel. Lath. Syn. vi. 375. Br. 

 Zool. ii. 182. Arct. Zool. ii. 528. 



The largest of the known Gulls. This bird was once, and once 

 only, seen from the ships, when they were high up in Baffin's Bay, 

 but at a distance too great to obtain a specimen. It was known 

 to Fabricius both in its mature and immature plumage; but he 

 was probably mistaken in considering the L. variiis of Briinnich 

 as a synonym of the young bird : that from its size is probably an 

 immature Herring Gull, The L. marinus is too well known to 

 need a particular description. 



19- Larus Glaucus. Glaucous Gull. 



L. Glaucus. Gmel. i. 600. Fabr. 100. Briin. no. 148. Miill. no. I69. Lath. Lid, 

 Orn. ii. 814. — Glaucous Gull. Lath. Si/n. vi. 374. Arct. Zool. ii. 532. Sf Supp. 70. 



Notwithstanding the confusion in which the larger species of 



Gulls 



