Richardson's arctic gull. 
509 
NA TA TORES. 
LARID^E. 
RICHARDSON'S ARCTIC GULL. 
Lestris Richardsonii. 
PLATE CXLIII. FIG. II. 
The Lestris Richardsonii, first characterized as a 
new species by Mr. Swainson, and named by him in 
compliment to Dr. Richardson, the arctic traveller, by 
whom it was brought home from the polar regions, had 
previously been confounded with the Lestris parasiticus 
of Linnaeus, from which it is readity distinguished by its 
shorter tail, together with many other characters. It is 
the commonest species upon our coast, the L. parasiticus 
being of rare occurrence : it breeds on several of the 
Orkney and Shetland Islands; on the latter, upon those 
of Noss, Unst, and Foula, upon each of which I have 
had the pleasure of seeing them in considerable num¬ 
bers. Here they breed in society, as many as fifty or 
sixty together, and seem to prefer those districts which 
are low and marshy, for the purposes of nidification, 
laying their eggs, nevertheless, upon some slight emi¬ 
nence of dry ground. On the contrary, amongst the 
very numerous small islands on the coast of Norway, 
they breed most commonly apart from each other, each 
pair taking possession of its separate island, upon the 
highest point of nearly all of which they are constantly 
to be seen perched, and upon it they usually lay their 
