KEY TO TIllv WATICR lURDS OF FI^ORIDA. 



47 



Length. 1-t: Win- 12: Tail, 5.50: I'.ill. 1.40: Tar- 

 sus, 1.30. Forehead not white; crown, includ- 

 ing- forehead, black : upper parts pearl gray : under 

 parts white : bill comparatively short and thick; 



bill and feet l)lack. 



Qelochelidon nilotica. 

 GulUbilled Tern. See 



page 194 



Length, <).oO: Wing, S. 30; Tail, 3.60: Lill, i.ro: 

 Tarsus. .70. Adult in summer — under parts black. 

 Adult in winter — under parts wliite : bill black ; 

 feet dusky brown. 



•ngth, t).2r> ; Wing. 7: Tail, 3.50 ; Dill, 1.20; Tar- 

 sus, .65. L'nder ]iarts white ; bill and feet yellow. 



Hydrochelidon nigra surina= 

 mensis. 

 Black Tern. See page 199 



Sterna antillarum. 



Least Tern. See page 197 



Family RHYNCIIOPID.E. Skimmers. 



Rliynchops nigra. 



Length, 18 to 20; Wing, 15 : Tail, 5.50; Bill (cul- 

 men), 2.70; Cionys, 4.25. Bill thin, knife-like, 



lower mandible the longer, basal half of hill 

 vermilion red, blackish at tip. (reneral plumage 

 Mack, white beneath. 



Rhynchops nigra. 

 Black Skimmer. See page 200 



