550 ORNITHOLOGY AND OOLOGY. 
DESCRIPTION. 
Adult. — On the forehead is a triangular white spot extending to the eye; crown, 
occiput, and a line from the eye to the upper mandible, 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 are 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, eight and three-quarters inches; wing, six and three-quarters; tail, three 
and a half inches. , 
Hab. — Texas to Labrador; western rivers. 
This handsome little bird is of similar habits, and is 
almost as abundant as the preceding. It breeds in the same 
localities, and, like the others, nests on the beach or bare 
rocks. The eggs are three innumber. They are a rounded 
ovoidal in form, and a grayish-cream tint in color: they are 
marked with spots and confluent blotches of different shades 
of brown and obscure-lilac, and vary in dimensions from 
1.25 by .90 inch to 1.15 by .91 inch. A large number of 
specimens from both the Southern and Northern States 
exhibit no appreciable difference either in size or markings. 
HYDROCHELIDON, Botr. 
Hydrochelidon, Bore, Isis (1822), 563. 
Bill rather short, strong, the upper mandible curving slightly to the tip; nostrils 
basal, lateral, and longitudinal, the frontal feathers reaching nearly to the opening; 
wings very long and pointed; tail moderate and emarginate; legs short; the ante- 
rior toes slender, with the webs deeply indented; hind toe small; claws slender and 
acute. 
HYDROCHELIDON PLUMBEA. — Wilson. 
The Short-tailed Tern. 
Sterna plumbea, Wilson. Am. Orn., VII. (1818) 83. 
Sterna nigra, Nuttall. Man., II. (1834) 282. Aud. Orn. Biog., III. (1885) 535; 
V. (1889) 642. J. Birds Am., VII. (1844) 116. 
DESCRIPTION. 
Adult.— Head, neck, breast, sides, and abdomen, black; lower tail coverts white; 
under covering of wings ashy-gray; back and wings dark plumbeous-gray; the 
fie wows 
a ar a os, 
