1878.] MR. H. SAUNDERS ON THE LARIN.E. 209 



into the possession of the Imperial Museum in 1818, when it re- 

 ceived from Professor Schreibers the MS. and unpublished name 

 of Larus collaris. In the interval between the publication of 

 the 4to edition of Ross's 'Voyage to Baffin's Bay' and the later 

 8vo edition (both of which bear the date of 1819), Ross, or Leach 

 (for, although under Ross's name, Leach was probably the real 

 authority) heard of Schreibers's name, and, jumping at the con- 

 clusion that Schreibers's bird was L. sabini, inserted the synonym 

 of X. collaris (Schr.) for that species in the 8vo edition. Had 

 Schreibers's description been published, his name would have con- 

 siderably antedated the present one. 



Genus Xema, Leach. 

 The real distinguishing character of this genus, as instituted by 

 Leach, is the forked tail; but the name has been improperly 

 employed by Boie and others for many other species. Leach, 

 however, denned it most clearly ; and a generic name should never 

 be used in any other sense than that of the founder. 



48. Xema sabinii (Sabine). 



Larus sabini, J. Sabine, Tr. Linn. Soc. xii. p. 520, pi. 29 (1818); 

 J. Wilson, 111. Ornith. pi. iii. (1831). 



"Xema sabini, Leach," J. Ross, App. Ross's Voy. Baff. Bay, p. 57 

 (1819), 4to ed. ; Steph. in Shaw's Gen. Zool. xiii. pt. i. p. 1 77, pi. 20 

 (1826); Eyton, Rarer Brit. B. p. 54 (1836). 



"Xema collaris (Schreibers)," Ross in App. Ross's Voy. Baf. 

 Bay, ii. p. 164 (1819), 8vo ed. (not in 4to ed.), nee Schreibers. 



Gavia sabini, Macgill. Man. Brit. Orn. ii. p. 241 (1842). 



Larus sabini, J. C. Ross, App. Ross's 2nd Vov. p. 37 (1835). 



Larus sabinii, Richardson, App. Parry's 2nd Voy. p. 360 (1825) ; 

 Sw. & Richs. F. Bor.-Am., Birds, p. 428 (1831); Middendorff, Sib. 

 Reis., Zool. ii. p. 244, pi. xxiv. fig. 5, xxv. fig. 1 (young and egg), 

 (1853). 



Xema sabinii, Bruch, J. f. Orn. 1855, p. 292; Lawr. B. of N. 

 Am. p. 856 (1860); Newton, P. Z. S. 1871, p. 57, pi. iv. fig. 5 

 (egg) ; Dresser, B. Europe, pt. xxxi. August 1874. 



Larus sabinei, Schl. M. P.-Bas, Lari, p. 44 (1863). 



Xema sabinei, Coues, B. of N.W. Am. p. 660 (1874-5) ; Reid, 

 Zoologist, 1877, p. 490 (Bermudas). 



Hub. Arctic America, breeding to the north of Upernavik, in 

 Greenland, and then across to the west, breeding in iUaska (Dall) ; 

 not rare in Plover Bay, Eastern Siberia (Dall), and breeding on the 

 tundras of the Taimyr, north of 74° (Middendorff). In autumn it 

 migrates southward ; and many specimens have from time to time 

 been obtained on the British coasts and those of the continent, as 

 far east as Holstein, and on the French coasts. Most of these are 

 birds of the year; but Dr. L. Bureau has an adult, with full black 

 hood, captured on the coast of Brittany on August 25th, 1872. In 

 America its southern range, as until now recorded, was down to New 

 York on the east, and to Great Salt Lake, Utah, on the west — 



Proc. Zool. Soc— 1878, No. XIV. 14 



