3° 



CHAPTER I 



/. typ. 

 Eur., W Sib. 



CHLIDONIAS NIGRA L. 



(Black Tern) 



sbsp. surinamensis Gmel. 

 Alas.-New York. 



/• typ. 

 Eur. (local)-S Mong., 

 and farther south. 



GELOCHELIDON NILOTICA Gmel. 



(Gull-billed Tern) 



sbsp. aranea Wils. 

 Atl. coast of N. Amer. 

 Virg.-Tex., W. Ind. 

 Other sbspp. farther south. 



sbsp. vanrossemi Bancr. 

 Calif. 



HYDROPROGNE CASPIA Pall, {tschcgrava auctt.) 

 (Caspian Tern) 



Eur.-Ussuri, Afr. 



N. Amer. (local): Calif., C Can., Atl. coast. 



LARUS ARGENT ATUS Pont. 



(Herring Gull) 



sbsp. thayeri W. S. Brks. 

 Arct. isl. of N. Amer. 



Several sbspp. farther south. 



/• typ. 



(Common Gull) 

 Eur.: Faeroes- Kanin 

 Penins. 



LARUS CANUS L. 



sbsp. kamtschatschensis 

 Bonap. 



Siber.-Kamch. 



sbsp. brachyrhynchus Rich. 



(Short-billed Gull) 

 NW N. Amer. 



LARUS HYPERBOREUS Gunn. 



(Glaucous Gull) 



Jan Mayen, Spitzb., Kola Penins.- Alas.-N Greenl. 



Petchora, arct. Sib. 



LARUS MARINUS L. 



(Great Black-backed Gull) 



Atl. coast of N. Amer. (Nova Scot.- Greenl.-Icel.-NW Eur., E to Petchora. 



Labr.). 



