BIRDS OF MINNESOTA. 25 



found along the Mississippi and its principal tributaries within 

 the State. 



Later it has fallen under my notice in other localities, but 

 only at considerable intervals. I know nothing of its habits. 



SPECIFIC CHARACTERS. 



A triangular white spot on the forehead extending to the 

 eye; occiput, crown, and a line from the eye to the upper man- 

 dible, deep black; entire upper plumage and wings clear bluish- 

 gray; first two primaries with the outer web and half the inner 

 next the shaft, grayish-black, ends of the same color, inner 

 margins white, the shafts of these two quills black; the other 

 primaries same color as the back with the inner margins white; 

 tail same color as the back except the outer margin of the 

 exterior feather, and the inner webs of the others at the base, 

 where they are white; entire under plumage silvery-white; 

 bill pale orange yellow; iris hazel; legs and feet, light orange- 

 red. 



Length, 8.75; wing, 6.75; tail, 3.50. 



Habitat, Northern South America, casually more northward 

 into British America. 



Later opportunities for more careful observations have en- 

 abled me to say that the Least Tern is not the rare bird gener- 

 ally represented, but on the other hand may be called fairly 

 common throughout the later spring and summer till into Sep- 

 tember, and occasionally a few remain even till the first part 

 of the following month. 



Two clutches of the eggs have been brought to me, — one in 

 June, 1887, and the other in July, two years later. They were 

 cream- colored with a grayish tint, and marked with small and 

 larger spots of varying shades of brown, some of which were 

 confluent. One or two gave the least possible suggestion of a 

 lilac wash. 



HYDROCHELIDON NIGRA SURINAMENSIS Gmelin. (77.) 



BLACK TERN. 



Of all the Terns that visit the State this species is the most 

 abundant. Arriving from the 7th to the 10th of May they seem 

 to take possession of the whole commonwealth simultaneously. 

 This remarkable uniformity of their vernal appearance in 

 widely severed localities of latitude I have long observed. 



Entirely insectivorous in their food, the first week or ten 

 days after their arrival they are almost incessantly on the wing, 

 in flocks of forty to a hundred, skimming the marshes, now 

 overflowed more or less, and bearing on the currentless waters 

 many kinds of insects, like crickets, grasshoppers, beetles and 

 spiders. Following this they are little seen except early in 



