110 
strictly Australian, and may be regarded as one of the anomalies of 
its fauna. 
556. Biziura lobata Yol. VII. PL 18. 
Family LARI DAE. 
Genus Larus. 
The members of this genus are distributed over the sea-shores of 
every, part of the globe. Only one species inhabits Australia, to 
which country it -is confined, and where it represents the Larus 
marinus of Europe and America. 
557. Lams Pacifieus Yol. VII. PL 19. 
Genus Xema. 
A genus of Gulls, the members of which are delicate in their 
structure, elegant in their appearance, and graceful in all their 
actions. Many species are found in Europe and America, and others 
inhabit Africa ; one species only has been characterized as Austra- 
lian, but I believe that another will be found in Torres’ Straits very 
similar to, but much larger than, the X . Jamesonii of the southern 
parts of that continent. 
558. Xema Jamesonii Yol. VII. PL 20. 
Subfamily — — ? 
Genus Lestris. 
The high latitudes of both the northern and southern hemispheres 
are frequented by parasitic Gulls. 
One species of this form has been found in the Australian Seas, 
and another has been discovered within the Antarctic circle. 
559. Lestris Catarractes Yol. VII. PL 21. 
Although I have figured and described this Australian bird as 
identical with the Skua Gull of Europe, it is likely that hereafter 
reasons may be found for separating them. 
In a letter just arrived from Mr. J. M‘Gillivray, dated on board 
H.M.S. Rattlesnake, Feb, 6, 1848, that gentleman says, “ The 
Lestris Catarractes was noticed on various occasions in different 
parts of the South Indian Ocean ; while off the Cape of Good Hope 
a solitary individual and subsequently two in company were seen. I 
have observed it following and hovering over a bait towing astern, 
and once saw it chase a Cape Petrel and force it to alight on the 
water. This bird seldom remained with us for more than half an 
hour at a time, during which it made a few circular flights about the 
ship.” 
Subfamily STERNINiE. 
The members of this family inhabiting Australia and Europe are 
nearly equal in number, and in each country examples of the same 
