152 
STERNA ARANEA* 
well as above, and, during- summer at least, seems to 
constitute the principal food of the present tern. In 
several which I opened, the stomach was crammed with 
a mass of these spiders alone ; these they frequently 
pick up from the pools as well as from the grass, dashing 
down on them in the manner of their tribe. Their 
voice is sharper and stronger than that of the common 
tern ; the bill is differently formed, being shorter, more 
rounded above, and thicker ; the tail is also much 
shorter, and less forked. They do not associate with 
the others, but keep in small parties by themselves. 
The marsh tern is fourteen inches in length, and 
thirty-four in extent ; bill, thick, much rounded above, 
and of a glossy blackness ; whole upper part of the 
head and hind neck, black ; whole upper part of the 
body, hoary white; shafts of the quill and tail-feathers, 
pure white ; line from the nostril under the eye, and 
whole lower parts, pure white ; tail, forked, the outer 
feathers about an inch and three quarters longer than 
the middle ones ; the wings extend upwards of two 
inches beyond the tail ; legs and feet, black ; hind toe, 
small, straight, and pointed. 
The female, as to plumage, differs in nothing from 
the male. The yearling birds, several of which I met 
with, have the plumage of the crown white at the 
surface, but dusky below j so that the boundaries of the 
black, as it w r ill be in the perfect bird, are clearly 
defined ; through the eye a line of black passes down 
the neck for about an inch, reaching about a quarter of 
an inch before it ; the bill is not so black as in the 
others; the legs and feet dull orange, smutted with 
brown or dusky; tips and edges of the primaries, 
blackish ; shafts, white. 
This species breeds in the salt marshes; the female 
drops her eggs, generally three or four in number, on 
the dry drift grass, without the slightest appearance of a 
nest; they are of a greenish olive, spotted with brown. 
A specimen of this tern has been deposited in the 
Museum of this city [Philadelphia.] 
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