6. STERNA. 123 



(1885) ; Goss, B. Kansas, p. 3 (1886 : breeds) ; A. O. U. Check- 

 list, N. Amer. B. p. 9o (1687); Ridgxo. Man. N. Amer. B. p. 46 

 (1887) ; Cooke, Bird-Miijr. Mississip. Vail. p. 58 (1888) ; Feilden, 

 Ibis, 1889, p. 502 (Barbados) ; Cory, B. West Indies, p. 280 (1889) ; 

 id. Cat. West-hid. B. p. m (1892) ; Rhoads, Pr. Philad. Acad. 

 1892, p. 101 (Texas) ; Ilartert, Ibis, 1893, pp. 310, 337 (Aruba I. 

 and Bonaire I.). 



Sterna minuta americana. Sundev. K. Vet.-Akad. Stockh. Forh. 1869, 

 p. 589 (St. Bartbolomew, West Indies). 



Sterna superciliaris, B/as. J.f. O. 186(J, p. 74 ; Gray, Hand-l. B. iii, 

 p. 121, no. 11066 (1871) ; Coues, Key N. Amer. B. p. 322 (1872) ; 

 Laur. Mem. Bast. Soc. N. H. ii. p. 318 (1874: Manzanilla, W. 

 Mexico) ; Cory, B. Bahamas, p. 213 (1880 : breeds) ; id. op. cit. 

 2nd ed. p. 213 (1890). 



Sterna superciliaris antillarura, Coues, B. N.-West, p. 692 (1874); 

 Merriam, B. Conn. p. 134 (1877) ; Sennett, Bull. U.S. Geol. 

 Surv. iv. p. 66 (1878: Rio Grande, Texas) ; Coues, Check-list N. 

 Amer. B. p. 123 (1882); Stearns S,- Coues, New Engl. Bird- 

 life, p. 374 (1883) ; Coues, Key N. Amer. B. 2nd ed. p. 776 

 (1884). 



Adult in hreeding-2ilumage. Differs from the preceding species in 

 having the upper mantle and tail of a darker and bluer gre}', and 

 only the two outer pairs of primaries have black shafts with black 

 webs on either side ; the black stripe on the inner web is also a 

 trifle narrower : bill stouter, the maxilla more curved, yellow, with 

 little black at the tip, though the amount varies ; tarsi and toes 

 orange-yellow. Total length 8-75 inches, eulmen 1*3, wing 6'55, 

 tail 3'6, depth of fork 1*8, tarsus 0'6, middle toe with claw 0'7. 

 The sexes seem to be alike externally. 



Adult in winter. Probably as in summer, with merely some ex- 

 tension of white on the lores and crown, and duller colours to the 

 biU and feet. I have never seen a specimen. 



Immature. Forehead and crown nearly white, orbital regions and 

 nape dull black ; the usual dark line along the carpal joint and 

 upper wing-coverts ; lower primaries dark grey, the upper ones 

 paler, with a brown tinge, and white on the inner margins : bill 

 nearly black ; tarsi dull brown. 



Young. Forehead and crown pale buff or dull white, with brown 

 flecks which become confluent round the eye and on the nape ; 

 feathers of the upper surface dull grey, with brown arrow-shaped 

 centres and buff or white margins ; primaries chiefly dark grey with 

 dark shafts : bill horn-colour ; feet yellowish brown. 



Nestling. Stoue-white, marbled with ash-brown above, dull white 

 below. 



Hah. Temperate and Tropical North America, occasionally visiting 

 Newfoundland and Labrador ; breeding along the Mississippi and 

 Missouri valleys from Dakota downwards, and on the coast from New 

 England down to the West Indies generally, the Leeward Islands 

 and Trinidad ; on the Pacific side from California to Mexico and 

 Central America. In winter occasionally to the West and South- 

 west coast of Africa. 



