Paraguay, Bolivia, and Southern Brazil. -ArS 



including tlie 1st of March several of these Terns were seen, 

 sometimes singly and sometimes in nairs^ passing along the 

 Atlantic coast, but generally very far out at sea. I had not 

 met with this species in the Ajo district before. It has a 

 very clear slirill crj^, which cannot be mistaken, 



266. Sterna trudeauii. 



Sterna trudeauii Arg. Orn. ii. p. 195; Saunders, Cat. B. 

 XXV. p. 130. 



a, b. ($ ^ ad. Los Ynglases, Ajo. Oct. 27, 1903. 



c. S acl. >, .., Nov. 1, 1908 



d. ? imm. Luiconia, Ajo. Feb. 2, 1909. 



e. J imm. Tuyu, „ Feb. 21, 1909. 

 /, •/. ? imm. „ „ Mar. 1, 1910. 

 Trudeau's Tern is, I think, the only resident Tern in the 



Ajo district, where it is quite plentiful, especially on the coast^ 

 and flocks of many hundreds can be seen any day. The 

 flight is low and graceful, and the cry a sort of " whew.'' 

 It is also met with on every lagoon and open sheet of water 

 inland. 



2G7. Sterna superciliaris. 



Sterna superciliaris Saunders^ Cat. B. xxv. p. 121. 



a. ^ ad. Riacho Ancho, N. Argentine. Aug. 1, 1909. 



b. S ^d. Desaguadcro, Paraguay. Aug. 29, 1909. 



c. S ^<^- Colonia Risso, „ Sept. 9, 1909. 



d. iS nestling. Colonia Risso, Paraguay. Sept. 9, 1909. 



e. S young. Near Puerto Braga, „ Sept. 21, 1909. 

 /. S young. Colonia Risso, ., Oct. 20, 1909. 

 The adults are in breeding-plumage ; that shot on the 



29th of August has still a few white feathers on the head, 

 and new black feathers are replacing them. 



This little Tern was fairly plentiful throughout the river 

 trip, and was found breeding, as described under Phaethusa 

 ma(/nirostris. As I stated there, it leaves the colony on being 

 disturbed, and I only secured one specimen on Sept. 9th, 

 when we were some time ashore. One or two returned, but 

 flew verv his-h and almost out of shot. 



