336 



LONG-WINGED SWIMMKRS ~ LONOIPENNES. 



fuliginou8-8late, the reiniges darker, nearly Mack terininally. Young, light phase: Head and neck 

 streaked with dusky brown and fulvous- l)uff, the latter usually predominating ; lower parts mow 

 or less distinctly harred, or spotted transversely, with the same. Upper j)arts brownish dusky, 

 all the I'eathei-s liordered terminally with fulvous-buff. Young, dark pluise : Prevailing color dark 

 brownish slate, the winj^s and tail darker. Middle of the neck, all round, indistinctly streakcl 

 with grayish white ; lower i)arts, except jugulum and upper ])art of brejist, barred with grayish 

 white, the bars broad and sharply defined on the crissum. Scai)ular8, interscapulai-s, wing-coverts, 

 upjier tail-covert«, and feathers of the rump narrowly tipped with pale dull buff. " Bill light blue, 

 dusky at the end ; iiis brown ; tai-si and basal jmrtion of the toes and webs light blue, the rest 

 black" (Auuubon). Downy young : Entirely silky grayish brown, lighter on the under surface. 



Adult, light phase. 



Total length, about 18.50 inches; extent, 40.00; wing, 11.80-13.15 (.worage, 12.67); middle 

 tail-feathers, 7.70-10.25 (8.(!C), the lateral rectri.e.s, 4.{)0-(!.2.") (5.40) ; culmen, 1.15-1.40 (1.-27) ; 

 tarsus, 1.50-1.85 (1.70) ; middle toe, 1.20-1.45 (1.34). i 



This species is almost if not quite as variable in idumage as the S. jmrnarinus, there being so 

 much individual variation in this respect that we have described only the light and dark extrciins 

 of coloration. 



As may be found noted under the head of that species, specimens occur which in every character 

 of plum.ige, including length of the niidiUe rectrices, are intermediate between the present bird ami 

 S. Umgicauflus. But there are two e.xcellent characters, to which our attention has been direetid 

 by Dr. L. Slejneger, which nuiy always be relied on. These consist (I) in the color of the taisi, 

 which in adult ^larrtsiViciw are always black, but in hmgknmlus light bluish (or, in dried skins, 

 more or less olivaceous) ; and (2) in the different proportion.s of the bill, parasiticus having tie 

 na.sal shield nnich longer, measured along the culmen, than the distance from the anterior bonier 

 of the nostril to the tip of the bill, these measurements being equal in lonykaudus. 



The Parasitic Jaeger is a northern species, although not as exclusively boreal as 

 are the ponuirlnus and the lonfficaudus. It is common both to Arctic America and to 

 the more northern portions of Asia and of Europe. Messrs. Evans and Stuigf 

 mention meeting with it on Spitzbergen. They saw it tormenting — as is its nianiur 

 — almost every flock of Kittiwake Gulls and Terns, but they met with neither its 

 nest, nor its eggs or young. Pennant narrates tliat the Arctic Skua — as he calls 

 this species — was breeding, at his time, on the islands of Islay, Jura, and Ronii ; 

 and Mr. A. G. More (" Ibis," 1865) thinks it highly probable that a few pairs still 

 linger in some of the numerous islands of the Hebrides. It is said to be extimt 

 at Jura. 



Thompson, in his "Birds of Ireland," states that a pair was shot in 1837 cm 

 the Island of Eona. He further states that they still breed in Sutherland aud in 



* Extreme and average measurements of twenty-two adults. 



