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 
confiuent. One or two gave the least possible suggestion of a 
lilac wash. 
HYDROCHELIDON NIGRA SURINAMENSIS GME vy. (77.) 
BLACK TERN. 
Of all the Terns that visit the State this species is the most 
abundant. Arriving from the7th 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 fiocks of forty to a hundred, skimming the marshes, now 
everflowed 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 
