548 ORNITHOLOGY AND OOLOGY. 



May, and as late as the 12th of July. I have seen, in the 

 space of a square rod, eggs, in which the chicks were about 

 ready to break the shell, and others that were apparently 

 but just laid ; and, close beside them both, were squatting 

 young birds almost fully grown and feathered. 



About the 15th of June is the period when the eggs of 

 this species are in the best condition in New England for 

 cabinet preservation ; the young then being, as a general 

 thing, scai'cely formed. 



Early in October, these birds begin to be scarce in our 

 latitude, and they spend the winter on the shores of the 

 southern gulf. 



STERNA U&GROVRA.— Naumann. 

 The Arctic Tern. 



Sterna macroura, Naumann. Isis (1819, 1847). 



Sterna Arctica, Temm. Man. d'Om., IL (1820) 742. Bon. Sjm. (1828), No. 

 287. Sw. and Rich. F. B. A., H. (1831) 414. Nutt. Man.. II. (1834)275. Aud. 

 Orn. Biog., IIL (1835) 366. 76., Birds Am., VII. (1844) 107. 



Desckiption. 



Adult. — Upper part of the head and hind neck black; back and wings light 

 grayish-blue; first primary deep-black on the outer web, dusky-gray on the inner 

 next the .shaft, and over the entire web at the end, inner margin of inner web white; 

 the next five primaries are bluish-gray on the outer web and on the inner web next 

 the shaft, this color extending over the entire web at the end, where it is blackish- 

 gray on the inner margin, the remaining part of inner web white; central tail 

 feathers and inner webs of the others white, the outer web of the outer tail feather 

 blackish-gray, the outer webs of the two next pale bluish-gray; rump, sides of the 

 head, and under tail coverts, white; under plumage bluish-gra}', of a lighter shade 

 than the back; bill deep-carmine; iris brown; legs and feet dark -crimson. 



Length, fourteen and a half inches; wing, ten and a half; tail, six and a half 

 inches. 



Mab. — Coast of the New-England States to Arctic seas; fur countries. 



This species is almost, if not equally, as abundant on our 

 shores in summer as the preceding. It breeds, in our lati- 

 tude, in the same localities and at the same time as the 

 other ; and its eggs are so exactly similar, that any descrip- 

 tion of either is impossible, by which they can be identified. 

 The only method that I know of to obtain authentic speci- 

 mens of each is, either to visit localities in which either 



