ORDER CHARADRIIFORMES. 141 



Genus THALASSEUS Boie. 



Thalasseus Boie, Isis von Oken, [X] 1822, Heft v (May), col. 563. Type, 

 by subs, desig., Sterna cantiaca Gmelin = Sterna sandvicensis Latham 

 (Wagler, 1832). (Cf. Op. 62, Internat. Comm. Zool. Nomencl.) 



Thalasseus maximus maximus (Boddaert). Royal Tern. [65.] 



Sterna maxima Boddaert, Table PI. Enl., 1783, 58. Based on the Hiron- 

 delle de Mer, de Cayenne Daubenton, PI. Enl., 988. (Cayenne.) 



Range. — -Breeds in the Bahamas, the West Indies, and on the South 

 Atlantic and Gulf coasts from Virginia to Texas; also on the Pacific coast of 

 Lower California and Mexico; ranging casually to Massachusetts; not rare in 

 summer from San Francisco Bay south to western Mexico. Winters from 

 Florida, Louisiana, the Bahamas, and California south to Brazil, Peru, and 

 Argentina. [An allied race occurs on the west coast of Africa.] 



Thalasseus elegans (Gambel). Elegant Tern. [66.] 



Sterna elegans Gambel, Proc. Acad. Nat. Sci. PhUa., IV, No. 6, Dec, 

 1848 [June 16, 1849], 129. (Mazatlan [Sinaloa], Pacific coast of Mexico.) 



Range. — Breeds on the coasts and islands of the Gulf of California and at 

 two points midway on the Pacific side of Lower California. Winters on the 

 Pacific coast south to Chile and occurs in autumn along the coast of California 

 north to San Francisco. Accidental at Corpus Christi, Texas. 



Thalasseus sandvicensis acuflavidus (Cabot). Cabot's Tern. [67.] 



Sterna acuflavida Cabot, Proc. Boston Soc. Nat. Hist., II, 1847, 257. 

 (Tancah, on the coast of Yucatan.) 



Range — Breeds on the Atlantic and Gulf coasts from Virginia and North 

 Carolina to Florida, Texas, British Honduras, the Bahamas, and West Indies. 

 Winters from Horida, the Bahamas, and West Indies to Central America, 

 Colombia, and Brazil, and on the Pacific coasts of Oaxaca and Guatemala. 

 Accidental in Ontario, Massachusetts, and New Jersey. [An allied race occurs 

 in Europe and northern Africa.] 



Genus HYDROPROGNE Kaup. 



Hydroprogne Kaup, Skizz. Entw.-Gesch. Eur. Thierw., 1829, 91. Type, 

 by subs, desig., Sterna caspia Pallas (Gray, 1846). 



Hydroprogne caspia imperator (Coues). Caspian Tern. [64.] 



Thalasseus imperator Coues, Proc. Acad. Nat. Sci. Phila., [XIV] 1862, 

 No. 10-12, Oct.-Dec. [Feb. 26, 1863], 538. (Interior of the fur coun- 

 tries, Hudson's Bay and Labrador = Fort Resolution, Great Slave Lake.) 



Range. — Breeds at Great Slave Lake, Lake Winnipeg, Lake Winnipegosis, 

 Klamath Lake, west-central California, central Lower California, on islands in 



