376 
with the Arctic Tern as General Sabine had done, twenty years 
previously, on the islands in Melville Bay.” 
The fact of Xema sahinii and Sterna macnira thus consorting 
together at their breeding haunts is another link in the connection 
between this small Gull and the Terns, to which it is so nearly 
allied by its forked tail and the slenderness of its bill and legs. 
In size it approximates to the Little Gull (Lariis minutus), and like 
that species has a black, or rather slate-grey coloured head, in its 
adult summer plumage. There are but two species yet known of 
the restricted genus Xema, of which X. sahinii is the type, and 
X. fiircatum a Neotropical and much larger form.* 
The first specimen obtained in Great Britain was probably that 
stated by Yarrell {‘ British Birds,’ vol. iii. p. 550) to have been shot 
at Milford Haven in 1839 ; and the first observed in Ireland was 
the bird described by Thompson (‘Birds of Ireland,’ vol. iii. p. 309) 
as killed in Belfast Bay in 1822. 
I have, fortunately, had the opportunity of comparing my own 
female, which, as before said, closely resembles the young bird 
figured by Gould, with the other Yarmouth specimen, the sex of 
which, as stated by Mr. Lowne may, I think, be fully relied on, as 
it is not only somewhat larger than mine, but the tints of the 
plumage are generally brighter. It differs, chieily, from my own in 
the following points : — 
The bill, though the same length, looks stouter, being less tapering 
in form. 
The feathers on the crown of the head and nape of the neck are 
darker in tint and more distinctly freckled. 
The white line over the eye and extending back, forms a marked 
feature, though scarcely traceable in mine, and the forehead, and 
feathers extending to the nostrils, are of a purer white. 
* Mr. H. Saunders, in a paper on the Larinae or Gulls (Proc. Zool. Society, 
1878, p. 210), speaks of this second species “as a gigantic Sabine’s Gull,” at 
present represented only in collections by two examples ; one in the British 
iffuseuni from Chatham Island, in the Galapagos group, and one in the Paris 
Museum, said to have been obtained at Monterey, California, but this locality 
seems doubtful. See Mr. 0. Salvin “on the avi-fauna of the Galapagos 
Archipelago” (Trans. Zool. Society, vol. ix. p. 506). Since this paper, 
however, has been in the printer’s hands, Mr. Saunders has informed me 
that he has, recently, received a third specimen of X. furcatum from the 
coast of Peru ; and two of X. sahinii. 
