MARSH TERN. 79 
ferently formed, being shorter, more rounded above, and 
thicker ; the tail is also much shorter, and less forked. They 
do not associate with 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 
‘The principal character we should assign for a ready distinction be- 
tween these two closely related species (in addition to the shorter, thicker, 
less compressed, and straighter bill, with its edges turned inwards in 
Anglica), consists in the tarsus, which in aranea (owing to its shortness 
and the extraordinary length of the nail) is of the same length as the 
middle toe, including the nail, whilst in Anglica it is nearly twice the 
length (owing to its superior length, and the shortness of the nail). 
The membranes of our bird are also much more scalloped. The habits of 
the two species are very different. The S. Anglica, confined to the sea- 
shores, feeds almost exclusively on strand birds,* and their eggs, some- 
times on fishes ; whilst the S. aranea, generally found on marshes, feeds 
exclusively on insects.” 
Bonaparte, and the authors of the “ Northern Zoology,” have men- 
tioned the following species as also found in North America :— 
1. S. cyana, Lath.—Inhabiting the tropical seas of America; common on 
the coasts of the southern States. 
2. S. Arctica, Temm.—WNorth. Zool., p. 114.—Bonaparte expresses a doubt 
that this is the true Arctica of Temm.; and the description in the ‘‘ North- 
ern Zoology ” points out some discrepancies. 
3. S. stolida.— Migrates to the North American coasts. 
Pheton, Linn, 
These birds, from general appearance, approach near to the terns 
(S. Caspia) ; but from the want of specimens, I am unable to enter into 
the proper situation of the form, except from the authority of others. 
Bonaparte places it between sula and plotus. The only American species 
is— 
1. P. thereus, Linn., tropic bird of Wilson’s List.—Common during sum- 
mer on the coasts of the southern States.—ED. 
* Is this correct? Does this tern kill other seafowl, and plunder their nests? 
—ED. 
