BIRDS OF NORTH AND MIDDLE AMERICA. 66 
Adult male.—Wing, 390-4384 (416.8); tail, 169-202.5 (189.3) 
exposed culmen, 46.2-53.5 (50.8); depth of bill at gonydeal angle 
12.4-14.2 (13.1); depth of bill at base, 16.5-18.5 (17.5); tarsus 
48-56 (52.7); middle toe, 46.2-53.3 (50.7). 
Adult female.—Wing, 406.5-425 (414.3); tail, 182.5-205 (193) 
exposed culmen, 48.5-51.5 (49.7); tarsus, 47-51 (48.9); middle toe 
45.7-52 (48.4).° . 
Galapagos Archipelago (Albemarle, Barrington, Brattle, Cham 
pion, Charles, Chatham, Cowley, Crossman, Culpepper, Dalrymple 
Daphne, Delano, Enderby, Gordon, Guy Fawkes, Hood, Indefati 
gable, James, Kicker, Narborough, Seymour, Tower, and Wenmar 
islands); casual off coast of southern California (Monterey Bay; of 
San Diego, April 14, 1895) ?, on Malpelo Island, off Bay of Panams 
(March 5, 1891) and on coast of Peru (Paracas Bay, Oct.). 
Larus furcatus Nesoux, Rev. Zool., 1840, 290 (‘‘Monterey” [California]; coll 
Paris Mus.); Voy. ‘Venus,’ Atlas, 1842, pl. 10.—Privost and Drs Murs 
Voy. ‘Venus,’ Ois., 1855, 277. 
[Xema] furcatus Brucu, Journ. fur Orn., 1853, 103 (‘‘Californien ”). 
[Xema] furcatum Gray, Hand-list, iii, 1871, 117, no. 11014.—Covgs, Key N 
Am. Birds, 1872, 317. 
Xema furcatum Cougs, Check List, 1873, no. 559; Birds Northwest, 1874, 66: 
(monogr.).—SaunpeErs, Proc. Zool. Soc. Lond., 1878, 210 (monogr.); 1882 
523, pl. 34 (Paracas Bay, Peru, Oct.; descr. and colored plate of young).— 
TaczANOWSKI, Orn. du Pérou, iii, 1886, 457.—Srreers, Auk, xxix, 1912 
233 (off Chatham Island, Galapagos, habits). 
Xema furcata Couns, Check List, 2d ed., 1882, no. 791.—Bairp, BREWER, anc 
Riveway, Water Birds N. Am., ii, 1884, 273—SaunpeErs, Cat. Bird 
Brit. Mus., xxv, 1896, 165 (Dalrymple Rock, near Chatham Island, Gala 
pagos: Paracas Bay, Peru).—Rortuscuitp and Hartert, Novit. Zool., vi 
1899, 190 (Wenman, Culpepper, Tower, and Hood Islands, Galapagos Archipel 
ago; descr. nest and eggs); ix, 1902, 412 (Wenman, Daphne, Guy Fawkes, anc 
Albemarle islands, Galapagos; hahits; descr. nest, eggs, young, etc.), 41! 
(Galapagos). 
X{[ema] furcata Coues, Key N. Am. Birds, 2d ed., 1884, 753.—Ripeway, Man. N 
Am. Birds, 1887, 38.—Roruscuitp and Hartert, Novit. Zool., vi, 1899, 20¢ 
(Galapagos). 
[Xema] furcata Forses and Rozinson, Bull. Liverp. Mus., ii, no. 2, 1899, 56. 
Xema (Creagrus) furcata AMERICAN ORNITHOLOGISTS’ Union, Check List, 1886 
350 (Hypothetical List, no. 4). 
[Creagrus] furcatus Bonaparts, Naumannia, 1854, 213; Compt. Rend., xlii, 1856 
771.—Bruca, Journ. fiir Orn., 1855, 292. _Saarre, Hand-list, i, 1899, 139. 
Creagrus furcatus LAWRENCE, in Baird, Rep. Pacific R. R. Surv., ix, 1858, 857.— 
Barrp, Cat. N. Am. Birds, 1859, no. 679.—Covgs, Proc. Ac. Nat. Sci. Phila. 
1862, 312 (monvgr.).—Brasrus, Journ. fir Orn., 1865, 370 (crit.)._Satvin 
Trans. Zool. Soc. Lond., ix, 1876, 506 (Dalrymple Rock, Chatham I., Gala 
pagos).—Ripa@way, Proc. U. 8. Nat. Mus., iti, 1880, 207 (Cat. N. Am. Birds 
no. 678); xii, 1890, 117 (Chatham I., Galapagos; full description); xix, 1896 
638 (Brattle, Hood, Chatham, off James, and Tower islands, Galapagos; Malpel< 
I., off Bay of Panama; etc.; descr., measurements, etc.); Nom. N. Am 
a Thirteen specimens. b Five specimens, 
