276 BRITISH BIRDS' EGGS. 



their neighbourhood, sucking their eggs whenever they are 

 left uncovered by their owners, and with unavoidable speed 

 of wing pursuing them over the surrounding sea, in order 

 to compel them to disgorge those fish which they have 

 just captured for themselves and their young ones." The 

 Richardson's Skua begins to breed early in June. 



THE ARCTIC SKUA. Lestris parasiticus. This species 

 was for some time confounded with the last, but was sepa- 

 rated from it by Mr. Swainson, who named the last after 

 Dr. Eicharclson, the Arctic traveller. The present is by far 

 the rarer species. The eggs are two in number, of a pale 

 olive-green blotched with reddish-brown. Another name 

 for this bird is "Buffon's Skua." 



THE CASPIAN TERN. Sterna Caspia. The Terns, of 

 which there are several species, are birds of elegant form, 

 and their powerful and graceful flight, together with their 

 long and pointed wings, and deeply-forked tails, have pro- 

 cured for them the name of Sea Swallows. They feed on 

 fish, and breed in company, making their nests either upon 

 shingly beaches or on the ledges of rocks. The Caspian 

 Tern is a species occasional only in its visits to the English 

 coasts, and partial in its distribution. It is reported to lay 

 its eggs, two or three in number, in a depression upon the 



