90 MANUAL OF PHILIPPINE BIRDS. 
“Coloration.—Similar to that of S. fluviatilis [= hirundo], except that 
the bill is always black and the {QF ave blackish. Adults are darker in 
color, both above and below, but the difference is not great. All the meas- 
urements appear identical, or nearly so, except those of the bill, which is 
altogether smaller, and measures about 45 mm. from the gape.” 
(Blanford.) 
“Adult in winter—Forehead flecked with white otherwise similar. 
“Tmmature.—Like that of fluviatilis [= hirundo] from which it can 
hardly be distinguished except by the color of the bill and feet and the 
somewhat smaller size and more delicate shape of the latter.” (Saunders.) 
80. STERNA BOREOTIS (Bangs). 
NORTHERN BERGIUS TERN, 
Sterna bergii SAUNDERS, Cat. Birds Brit. Mus. (1896), 25, 89 (part) ; 
SHARPE, Hand-List (1899), 1, 136 (part). 
Sterna bergii boreotis BANGS, Bull. Mus. Comp. Zool. (1901), 36, 256. 
Sterna boreotis McGREGoR and WorcESTER, Hand-List (1906), 20. 
Ga-bi-o’-ta, general name for gulls and terns. 
Agutaya (McGregor) ; Balabae (Steere); Bantayan (McGregor) ; Bohol (Eve- 
rett, McGregor); Calamianes (Bourns & Worcester); Caluya (Porter); Cebu 
(Bourns & Worcester, McGregor); Cuyo (McGregor); Guimaras (Bourns & 
Worcester) ; Leyte (Hverett); Luzon (Bowrns & Worcester); Masbate (Bourns 
¢. Worcester) ; Mindanao (Murray, Koch & Schadenberg, Steere Exp., Bourns & 
Worcester) ; Mindoro (Porter); Negros (Bourns é Worcester, Keay); Palawan 
(Whitehead, Platen, Bourns & Worcester, White) ; Panay (Bourns € Worcester) ; 
Pata (Mearns); Romblon (Bourns & Worcester, McGregor); Samar (Bourns & 
Worcester) ; Sibuyan (Bourns & Worcester); Siquijor (Bourns & Worcester, 
Celestino); Sulu (Bourns & Worcester); Tablas (Bourns & Worcester); Tawi 
Tawi (Bourns & Worcester). Liu Kiu Islands and Northern China Sea. 
“Adult male in full breeding plumage (type).—Forehead, cheeks, lores, 
ear-coverts, neck all round, and whole under parts, including lining of 
wing and bend of wing, pure white; crown and long occipital crest 
glossy black; mantle, wings, rump, upper tail-coverts, and upper surface 
of middle rectrices dark smoke-gray, darkest on wings and middle of 
back, where the color is almost mouse-gray; primary quills white; first 
primary with outer web, a band along quill on inner web and tip blackish, 
with a silvery suffusion which is most marked toward center of feather ; 
broad outer margin of inner web, below the black tip, white; second 
primary similar but black tip deeper in color and extending a short 
distance down outer margin of inner web, thus inclosing the white of 
inner web for a short distance; third, fourth, and fifth primaries like 
second, but black tip gradually growing deeper in color; outer rectrices 
above pale smoke-gray at tips and along shafts, pale grayish white toward 
base; second and third rectrices darker on the outer webs and at tip and 
whitish toward base of inner webs. Bill in dried specimen, dull yellow 
