390 TEN YEAES IN SWEDEN. 



dentate) ; compressed at the sides., and pointed ; front toes 

 webbed. 



Gen. Sterna j L. Terns. 



Beak moderate, straight, slender, sharp pointed at the 

 tip ; mandibles equal ; mental angle in the lower one very 

 little projecting ; nostrils small, pervious, basal ; legs short ; 

 outer toe longer than the inner ; membranes or webs deeply 

 notched; wings long, acuminated, pointed; first feather 

 longest ; tail generally forked, often with the side feathers 

 far projecting, as in the swallow. 



In both the gulls and the terns the tail in the young 

 bird is always even. May all be considered as summer 

 migrants to the north, though many occasionally remain 

 off the southern coast during the winter. 



White or Sea Terns. 

 220. STERNA CASPIA, Pall. Skran Tiirna. The Caspian 



Tern. D. F. 



The largest of all the European terns ; beak large, 

 thick, deep red ; legs black ; tarsus 1-^ in. ; tail not 

 deeply cloven; length 22 in.; beak 2|- in., ^ in. 

 high ; tail 5| in., much shorter than the wings. 

 Spring dress : whole of the head and back of the neck 

 black ; mantle pale ash-blue ; wing feathers on the tips and 

 inner fan slate -blue ; sides of the head, breast, and under 

 parts pure white ; iris red-brown. 



Winter dress : forehead white ; neck spotted with black 

 and white ; the rest as in spring. 



Young : spotted with brown ; beak brownish. 

 Is a very local bird. A few pairs breed yearly on the 

 Wener, and it has been killed as far north as Tornea, but 

 is certainly rare in Sweden. Seems to breed commonly on 

 the Isle of Sylt, in Denmark. Eggs three, considerably 

 larger than those of the common gull, smooth, of a light 

 drab colour, with large and small purple brown spots, 

 strewed over the whole surface of the egg. The spots are 

 wide apart, leaving the ground colour very apparent, and 



