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340 



LONO-WINGKD SWTMMEUS - LONGIPEXNES. 



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ivctiiccf*, 10 50-1 ». no (12.80) ; liitcral nrtrici's -1 T.Vfi.W fr).2r)) ; ciiliiieii, 1.10-1.30 (1.19) ; tarsus, 

 L.'iO-l.HO (l.C.d) ; middle toe, l.OS-1.30 (l.iOi.' 



It i.-- soiiu'what ciiiious that in the i-iitiiv series of ei}»hte('ii exniiiples of tliin upecies eoiitaincd 

 in the collection of the National lluseuiii there i.-i not a single youiij,' bird, nor one represent in;; 

 a melanotic phase, all liein>; in the pliiiiia<^'e ilescribctl aliove. The only notable variation in this 

 Series consists in the e.xtent of the jdumbeous of the under surface of the body, a very few speci- 

 mens haviii^j this conlined to the posterior portions, the abdomen beinn white, just u.s in S. ptiru- 

 silinm. Usually, the two species may be readily distiii<^'uished by this restriction of the plumbeous 

 iniderneath, in S. iiantnitictt^, and its extension forward over the abdomen, almost or ipiite to the 

 breast, in S. Umiiicnudit.i. It is sometimes, thouj^di very rarely, dillicult to distin^'uish the two even 

 by the lenj;th of the central rectrices ; om- example of A'. jMnmilifuii haviu}^' these feathers lO.ii.j 

 inches lon^ and narrower than usual, while un indiviilual of S. lowiieamlun has them only 10..')() 

 loiij,'. ,nd liroader than in most examples of that species. Upon the whole, there is sometimes a 

 very close resemblance between these two forms in their normal phase of coloration (the only one 

 in which we have seen S. lomjicaudns). 



In fact, there can be no (luestion that in every character of plumnfje or coloration, indudin;,' 

 the lenjjth and breadth of the middle rectrices, the number of primaries havinj,' white shafts, the 

 ndative extent of <,'ray and white on the lower parts, etc., the two species do, in some sjieciniens, 

 completely inte)'},'rade, notwilhstandinj; the fact that typical examples may be very readily distin- 

 guished. The sha|)e of the bill and the color of the tai-si in the adults, however, it is believed 

 are constantly dillerent in the two siMJcics, as statetl imder the head of S. parasiticus and in the 

 synopsis of the si)ecies. 



These intermediate specimens may, of course, be hybrids ; but it seems more reasonable to 

 suppose that the two forms represent merely extreme modifications of one species. 



BufFon's Skua partakes of all the iieculiarities of this strongly characterized genus, 

 especially in its Arctic ilistriiuition. It appears to be the most northern of its 

 family, and to have, during the season wlien it is not breeding, a somewhat wider 

 range of migration than the others. In the summer it is fomul in all parts of tiui 

 region near the. Arctic Circle, breeding from Siberia around the circuit, including 

 Northern Asia, Europe, and America, and the Arctic islands. 



It is a resident s])ecies in CJreeidand, and is also found in Iceland, although not 

 given by Faber, who confounded it with the jmrasltirus. In 1858 ISlr. WoUey and 

 Professor Newton met with it several times near Kyrkjnvogn ; and others are men- 

 tioned fis having been obtained elsewhere. Mr. Uernard Iloss procured sjiecimens of 

 this bird at various points on the ^Fackenzie ; ^Ir. Murray mentions having seen it 

 on Hudson's Bay ; and Captain Blakiston received specimens from that region. 



According to Sir John Kichardson, it inhabits the Arctic sea-coasts of America as 

 well as of Europe, in the summer, migrating in winter to more temperate localities. 

 Numerous specimens of this Gull were brought back by the Arctic expeditions from 

 JNlelville I'eninsula and the North Georgian Islands. 



Mr. A. G. More states (" Ibis," 1865), on the authority of ISIr. K. G. Shearer, of 

 Ulbster House-wick, that some seven or eight years before that time a few pairs 

 of the Long-tailed Skua could always be found breeding at that place, together witli 

 the more common species, on a large inland flat studded with small dark lochs. In 

 18G0 a pair of these Skuas was shot on this ground during the breeding-season; and 

 in June, 18G2, a pair was obtained on one of the Outer Hebrides, where these birds 

 were probably breeding. 



Captain AV. H. Feilden ('• Ibis," October, 1877) states that this was the only species 

 of Skua Gull which the Expedition of 1875-1876 saw in Smith's Sound, wliere it arrived 

 in considerable numbers in the neighborhood of the winter quarters of the party durin;.( 



^ Extreme and average uicasuremcuts of eighteen adults. 



