FAMILY LARFDJE. 



-GULLS AND TKENS. 



35 



FAMILY LARID^. 



GULLS AND TERNS. 



SUBFAMILY LARIN^. GULLS. 



Tail, usually nearly square. 



GrOUI' 1. Wing, 9.50 to 11 inches long. See page 36. 

 Group 2. Wing, 11 to 13 inches long. See page 36. 

 Group 3. Wing, 13 to 15 inches long. See page 38. 

 Group 4. Wing, 15 to 17 inches long. See page 38. 



Section 1. Length, over 21 ; bill, over 2; underparts, white. See page 38. 



Section 2. Length, over 21 ; bill, over 2 ; underparts, not white. See page 39. 



Section 3. Lengtli, over 21 ; bill, under 2; underparts, white. See page 39. 



Section 4. Length, over 21 ; bill, under 2 ; underparts, not white. See page 40. 



Section 5. Length, under 21. See page 40. 

 Group 5. Wing, over 17 inches long. See page 40. 



SUBFAMILY STERNIN.E. TERNS. 



Tail, usually eokked. 



""^ Group 1. Wing, 5. .50 to 7. .50 inches long. See page 41. 



Group 2. Wing, 7.50 to 8. .50 inches long. See page 41. 



Group 3. Wing, 8.50 to 9. .50 inches long. See page 41. 



Group 4. Wing, 9.50 to 11 inches long. See page 41. 

 Group 5. Wing, 11 to 13 inches long. See page 43. 

 Group 6. Wing, 13 to 17 inches long. See page 43. 

 Group 7. Wing, over 17 inches long. See page 43, 



