LARUS DOMINICANUS. 197 



415. STERNA SUPERCILIARIS, Vieill. 

 (EYEBROWED TERN.) 



Sterna superciliaris, Scl. et Salv. Nomencl. p. 147 ; iid. P. Z. S. 1871, p. 671 ; 

 Durnford, Ibis, 1877, p. 201 (Buenos Ayres) ; White, P. Z. S. 1882, p. 628 

 (Misiones) : Sounder 8, P. Z. S. 1876, p. 662. Sterna argentea, Burm. La- 

 Plata Iteise, ii. p. 519 (Parand). 



Description. Forehead and underparts white ; loral stripe, head, and nape 

 black ; back, rump, inner primaries, and inner web of tail pale slate-grey ; outer 

 primaries blackish ; bill yellow ; legs and feet olive-yellow : whole length 8*5 

 inches, wing 7*0. In the young bird the crown is grey. 



Hob. The large rivers and the coast on the east side of South 

 America. 



This is a little Tern, belonging to the same group as the European 

 Sterna minuta, with a uniform pale yellow bill. Durnford met with it 

 at Baradero, and says that it frequents shallow inland lagoons and 

 small streams ; but is also found on the Rio de la Plata. Dr. Burmeister 

 obtained it on the Parana, and White at Itapua, Misiones. Saunders 

 shot it on the Huallaga, in Peru, 2800 miles inland. 



416. LARUS DOMINICANUS, Licht. 

 (DOMINICAN GULL.) 



Lams dominicanus, Scl. et Salv. Nomencl. p. 148 j iid. P. Z. S. 1871, p. 576; 

 Durnford, Ibis, 1877, p. 45 (Chupat) et p. 201 (Buenos Ayres), et 

 1878, p. 405 (Chupat) ; Barrows, Auk, 1884, p. 316 (Pampas) ; Saunders, 

 P. Z. S. 1878, p. 180 ; Withington, Ibis, 1888, p. 472 (Lomas de Zamora). 

 Larus vociferus, Burm. La-Plata Reise, ii. p. 518 (Buenos Ayres). 



Description. Mantle brownish-black ; primaries black, with white tips, and 

 a subapical patch in old birds ; rest of plumage white ; bill yellow, orange 

 at angle of lower mandible ; legs and feet olive : whole length 21'0-22'0 inches, 

 wing 17'0-18'0. Young mottled brown. 



Hob. Both coasts of South America, from Peru on the west and Rio 

 on the east, to Patagonia and Falkland Islands. 



The Dominican Gull, which belongs to the same section of the group 

 as the well-known Black-backed Gulls of Europe, is common through- 

 out the Plata district in winter, from April to August. During the 

 summer months it confines itself to the Atlantic coast, and breeds in 

 large numbers in the neighbourhood of Bahia Blanca, on the extensive 

 sand-banks and mud-flats there ; and in other suitable localities further 

 south. Durnford found it nesting at Tombo Point, sixty miles south 

 of the Chupat river. 



At the approach of cold weather the Dominican Gulls leave the 



