348 On the Birds of the Weddell and adjacent Seas. 
and hence it is only possible to discriminate with certainty 
between the two species by reference to the specimens 
obtained. No doubt, however, all the Skuas seen south of 
the Antarctic Circle belonged to the species named after 
Dr. McCormick. 
There are only two skins of this Skua in the collection 
brought home by the ‘ Scotia.’ The first of these, an adult, 
was procured on March 10th, 1903, in 66° 40’ S. and 
40° 35’ W., or the lowest latitude in which this species has, 
I believe, been obtained, except the example alluded to by 
me (‘ Ibis,’ 1906, p. 182) as captured at the South Orkneys 
by the Argentine observers in 1904. 
The second example, an adult male, was shot alongside the 
ship on March 9th, 1904, in 74° S. and 22° W. The 
‘ Scotia’ was then fast in the pack and about two miles off 
the Great Ice Barrier at Coats Land. Many of these birds 
were then present, as were also numerous Giant and Snowy 
Petrels and Arctic Terns (Sterna macrura). 
The Antarctic Skua (MM. antarctica) did not oceur with 
certainty beyond 62° 49’ S. (38° 12’ W.). 
CuHrontis ALBA (Gmelin). 
Chionis alba Cat. Birds, xxiv. p. 710. 
This bird, the only one found in the regions treated of that 
may be regarded as a terrestrial or, to speak more correctly, 
a semiterrestrial species, was several times observed at sea 
during the first voyage of the ‘ Scotia.’ It does not, however, 
penetrate into the Weddell Sea, but was met with when the 
ship was running eastwards from the South Orkneys towards 
the Sandwich Group in the late summer of 1903. 
During this voyage the White Sheathbill was observed on 
three occasions. First, on February 6th, in lat. 60° 10’ 8S. 
(42° 35’ W.), when the‘ Scotia’ was a good way off the edge 
of the ice. Here this species, along with Banks’s Whale- 
Bird, Cape, Wilson’s, and Snowy Petrels, followed in the 
wake of the ship during the day. Again, on February 8th, 
in 59° 44’ S. (86° 40’ W.), or about midway between the 
Orkney and Sandwich Groups and 300 miles from land, 
