TO THE BIRDS OF EASTERN NORTH AMERICA. 
KEY 
Roseate Tern. 
Winter. 
Forster’s Tern. 
Common Tern. 
\ 
| 
| 
| 
Gull-billed Tern. 
yarying with age 
the top of the head entirely black, part of the year, 
Least Tern. 
Adult Terns (except the Noddy) have 
and season, 
