5()2 



PALMIPEDES. 



SUB^FAMTLY III. 



Sterxin.e. 



The Terns. 



Gen. Charac— Bill more or less lengthened, p;enerally slender, straight, with 

 the culraen sometimes curved at the tip, which is acute; the nostrils basal, 

 lateral, and linear; the wings very long and pointed; the tail long, and 

 more or less forked ; the tarsi usuall}' short and slender; the toes of various 

 lengths and more or less webbed, the hind toe long and slender. 



Fig. 21o.— thk common tkr.n. 

 {Sterna Ilirundo.) 



These birds are distributed tlirougliont both lieTiii- 

 spberes, migrating in flocks from place to place^ 

 according to tlie season. Tliey usually frequent the 

 sea-coasts or salt-marshes, but are occasionally seen 

 on the borders of inland lakes and rivers. They are 

 continually on the wing, and their flight is lofty, of 

 long continuance, and extended far from land. 

 When seeking their food, they generally wheel 

 round in large circles, or hover over their prey, and 



