250 BIRDS OF ILLINOIS. 



Total length, about 9.25-9. 75 inches; extent, 24.00-25.00 ; wing, 8.25; tail, 3.75. its fork, .90 ; 

 culmen. 1.10; depth of bill at base, .25; tarsus, .68; middle too (with claw), .90. 



In most parts of the Mississippi Valley, as well as the more 

 western portions of the continent, this is decidedly the most 

 numerous of the terns. It inhabits reedy marshes, but may 

 also sometimes be seen "hawking" for dragon-flies, grasshoppers, 

 and other insects, over meadows or fields some distance from 

 water, uttering a harsh 7ir/, 7,vv7\ l-t>!k, as it flies, particularly 

 if two or more be together or near one another. It is very un- 

 suspicious. 



