1876.] MR. H. SAUNDERS ON THE STERNIN^E. 651 



from the Common to the Arctic Tern. There could be no objection 

 to their discarding 8. hirundo for the former and adopting 8. fiuvia- 

 tilis ; but these violent transfers must always be productive of con- 

 fusion even when justifiable ; and in this case it seems to me that 

 the original description is so ambiguous that they would have done 

 better to discard 8. hirundo altogether, and to adopt the first name 

 about which there could be no mistake — a step which, much as I 

 dislike to differ from such high authorities upon nomenclature, I 

 feel compelled to take. 



This species is the 8. paradisea of Briinnich (Orn. Bor. p. 42 

 (1764) — a pre-Linnsean name, which is not available. I notice it, 

 however, because this name has frequently been employed for the 

 Roseate Tern (8. dougalli), a bird with which Briinnich was unac- 

 quainted. From the plate and description I always imagined that 

 8. pikei was an immature bird of this species, and am glad to have 

 this opinion confirmed by Dr. Elliott Coues, who has lately reex- 

 amined the type. 



With regard to S. portlandica, Mr. W. Brewer's investigations 

 and the latest information from American sources leave little doubt 

 that it is only an immature example of this species. 



The Arctic Tern ranges along the coasts of northern Europe, Asia, 

 and America ; in winter it visits the African coast, descending as far 

 as Walwich Bay ; and I have an example obtained by Wucherer off 

 Bahia, the only instance known of its occurrence so far south on the 

 American side ; it is possible, however, that the bird mentioned by 

 Philippi and Landbeck, Cat. Av. Chilenas, 49 (1869), may be this 

 species. 



Sterna forsteri, Nutt. 



Sterna hirundo, Svv. & Rich. F. Bor.-Am. p. 412 (1831), nee 

 auct. (Saskatchewan River). 



Sterna forsteri, Nuttall, Man. Orn. ii. p. 274, note (1834) ; 

 Lawr. B. N. Am. p. 862 (1858); Coues, P. Phil. Acad. 1862, 

 p. 544 ; Bias. J. f. Orn. 1866, p. 74 ; Scl. & Salv. P. Z. S. 1871, 

 p. 569 ; G-ray, Hand-list, iii. p. 118 (1871) ; Coues, B. N.W. Am. 

 p. 676 (1874). 



Sterna lavelli, Aud. Orn. Biog. v. (1839) p. 122, pi. 409. fig. 1, 

 and of Lawr. &c. {fide Coues) ; Gray, Hand-list, iii. p. 118 (1871). 



A rather stouter and larger species than S . fiuviatilis, this species 

 may always be distinguished by its having the outer webs of the 

 long tail-streamers white, whereas in the allied species they are 

 dusky. In the ' Birds of the North West ' (/. s. c.) Dr. Coues 

 gives the differential diagnoses of S. forsteri, fiuviatilis, and macrura ; 

 and to these I have nothing to add. 



In summer this Tern breeds in the interior of British America and in 

 Wisconsin; but at other seasons it is generally distributed throughout 

 the United States, and goes down as far as Guatemala, on both the Pa- 

 cific and Atlantic side, and even to the latitude of Pernambuco, Brazil, 

 thus nearly impinging upon thenorthern limits of S. trudeaui, a species 

 to which, in winter plumage only, it bears a superficial resemblance. 



[15] 



