BIRDS OF NORTH AND MIDDLE AMERICA. 559 



Q,a. Bill much more slender, its depth at base equal to less than one-iifth the length of 

 exposed culmen; tail much less than half as long as wing, slightly forked, the 

 outermost rectrices little if any longer than middle pair, none of the rec trices 

 distinctly acuminate; shafts of primaries and rectrices not distinctly (sometimes 

 not at all) dusky. (Marquesas Islands, central Pacific Ocean.) 



Gygis microrhyncha (extralimital)." 



GYGIS ALBA CANDIDA (Gmelin)?;> 



HAWAIIAN WHITE TERN1 



Adults (sexes alike). — Whole plumage immaculate pure white; 

 shafts of primaries and rectrices brownish or dusky, and margin of 

 eyelids black; bill black (in life ''black at the tip, shading tlirough 

 purple to indigo blue at the base");" iris blue;*^ legs and feet "dark 

 brown, the webs yellow."'^ 



Immature. — Similar to adults, but with a postocular spot and 

 anterior margin to eyelids black, and shafts of primaries and rectrices 

 black or dusky. 



Young. — Similar to the immature plumage (as described above), 

 but back, scapulars, and tertials tinged or washed with russet or 

 browii, lesser wing coverts and middle rectrices margined terminally 

 with brown or russet, shafts of primaries ohve-brown, and shafts of 



(Fernando Noronha, Trinidad and Ascension islands); Sharpe, Journ. Linn. Soc, 

 XX, 1890, 480 (Fernando Noronha); Ihering, Revista Mus. Paulista, iv, 1900, 294 

 (descr. eggs.). — Gygis crairfordi NicoU, Bull. Brit. Orn. Club, xvi, no. cxxvi, July 10, 

 1906, 102; Ibis, 1906, 669 (South Trinidad Island.) 



(2) Gygis alba monte. — Gygis alba monte Mathews, Birds Australia, ii, no. 4, Nov. 1, 

 1912, 443 (Seychelles, breeding). 



(3) Gygis alba pacifica. — Sterna pacifica Lesson, Hist. Nat. Mam. et Ois., x, 1837, 

 156 (Low Archipelago, Pacific Ocean). — Gygis alba pacifica Mathews, Birds Australia, 

 ii, pt. 4, Nov. 1, 1912, 443 (Society Islands, Samoa, etc.). — Sterna nivea Bennett, 

 Narrative Whaling Voy., i, 1840, 370 (Caroline Atoll). 



(4) Gygis alba royana. — Gygis alba royana Mathews, Birds Australia, ii, pt. 4, Nov. 

 1, 1912, 433, 443 (Kermadec Island and Norfolk Island, breeding; Friendly Islands?). 



(5) Gygis alba kittlitzi. — Gygis alba kittlitzi llartert, Katal. Vogelsamml. Senckenb. 

 1891, 237 (Caroline Islands); Mathews, Birds Australia, ii, pt. 4, 1912, 443 (Caroline 

 group; Mariannes?). 



(6) Gygis alba Candida (Synonymy given separately.) 



o Gygis microrhyncha Saunders, Proc. Zool. Soc. Lond., 1876, 668 and cut (Marquesas 

 Islands, central Pacific Ocean; coll. Brit. Mus.); Cat. Birds Brit. Mus., xxv, 1896, 

 152; Tristram, Ibis, 1881, 252; Cat. Coll. Birds, 1889, 10; Wiglesworth, Abh. Zool. 

 Mus. Dresden, 1890-91 (1892), no. \d, 78; Kaiser, Journ. fur Orn., 1902, 255 (Nauru 

 Island). 



& Scantiness of material (I have seen no specimens at all from the American side of 

 the Pacific) and the fragmentary manner in which the various forms are treated by 

 the most recent re\aser of the group, Mr. Gregory Mathews, necessitates the interro- 

 gation mark in connection with the subspecific name. The Pacific-American sub- 

 species is referred tentatively to G. a. Candida as being the nearest form geographically : 

 but it may be different. 



c Gifford, Proc. Calif. Acad. Sci., 4th ser., u, 1913, 32. 



■* Saunders, Cat. Birds Brit. Mus., xxv, 1896, 150. 



