322 MR. H. SAUNDERS ON THE STERCORARIIN.E. [Mar. 21, 



that of the Antarctic Skua, it seems to me that only the want of a 

 sufficient series of both species for comparison can ever have led to 

 their being united ; for undoubtedly the distinctness of many other 

 birds as species is unhesitatingly acknowledged on much slighter 

 grounds. In the examination of a large series I have never met 

 with any northern Skua with the stout deep bill with its well- 

 marked angle at the gonys which invariably characterizes the 

 southern bird ; and if mere colour is taken into consideration, the 

 total absence of rufous both on the underparts, the axillaries, and 

 the under wing-coverts serves- to distinguish the Antarctic Skua at a 

 glance. But whilst perfectly distinguishable from S. catarrhactes, 

 it presents three interesting variations in the course of its range, 

 which I have been enabled to trace by the aid of a fine series in the 

 British Museum. From Campbell's Island in 54° S., 168° E., up 

 to Norfolk Island, in 29° S. (its most northern known range), past 

 Kerguelen's Island, the Crozets, and up to the Cape of Good Hope, 

 where Layard observed it in April, the specimens all agree in their 

 remarkable uniformity of sooty-brown plumage, there being few, if 

 any, striations even upon the feathers of the neck, whilst the size of 

 some of the examples is .enormous, the primaries measuring 16 and 

 1 7 inches from carpal joint to tips of primaries. The Falkland-Island 

 Skuas, locally known as " Cape-Egmont Hens " and " Sea-Hens," 

 are decidedly smaller, and the acuminate feathers of the neck and 

 shoulders are distinctly streaked with yellowish white, although the 

 general sooty appearance is preserved. But in three specimens ob- 

 tained during the voyage of the 'Erebus' and 'Terror,' on the edge 

 of the pack-ice, the upper parts are somewhat less dusky than in the 

 Falkland-Island birds, and the tips of the feathers of the breast are 

 tinted with yellowish, though the underparts of the feathers retain 

 their sooty hue, whilst the acuminate feathers of the neck form a 

 complete ring of yellow verging upon golden, and, by contrast with 

 the darker colour of the crown, giving somewhat the appearance of a 

 hood. In general dimensions this form is somewhat smaller than 

 the preceding, and the bill is even more short and stout in propor- 

 tion ; but the general characters of resemblance are preserved through- 

 out, the under wing-coverts and axillaries being dark smoke-coloured, 

 whilst the lighter hue of the underparts extends no further than the 

 tips of the feathers, and may be due to climatic influences. In their 

 somewhat bleached appearance and the closer texture of the feathers 

 about the base of the bill, these three birds have the appearance of 

 permanent inhabitants of inhospitable circumpolar regions, whilst 

 the Falkland-Island birds seem to be a connecting link between this 

 and the larger form, whose range is principally within more tempe- 

 rate climr.tes, where the conditions of existence are easier. 



It is most probable that Bonaparte's &. madagascarensis belongs 

 to this species, as the late Commander Spurling saw what he supposed 

 to be a Great Skua off the Comoro Islands, and this would bring its 

 extreme range up to about 12° S., leaving even then an interval of 

 more than 40° of latitude between it and the most southerly known 

 range of S r catarrhactes. Neither has true S. antarcticus been 

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