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and Mediterranean Seas, but to be of rare or acci- 
dental occurrence on the western coasts of Europe. 
It has also been found in Senegal, and at the Cape 
of Good Hope. The Caspian Tern is incessantly 
on the wing, sustaining its flight with apparent 
ease, and swims buoyantly on the water, but never 
dives. Its principal food is fish, or animal matters 
left by the retiring tide. It is said to lay ina hole 
in the sand, or on the bare rocks near the edge of 
the sea, two or three eggs of a yellowish stone 
colour, spotted with ash grey and dark red brown. 
TERN, COMMON. 
SEA SwALLow. 
STERNA HIRUNDO, Lin. 
This species visits Germany, Holland, Switzer- 
land, France, Spain, Italy, and Madeira. Specimens 
have also been received from Trebizond. It is 
common on all our sandy shores, arriving early in 
May, and departing in September. It breeds on 
unfrequented sands, headlands, islands, and some- 
times in rocky places, depositing its eggs in a slight 
hollow. The eggs, generally three in number, vary 
greatly in colour, specimens being seen of a greyish 
yellow, olivaceous, or brownish hue, blotched with 
black and purplish grey. The food of the Common 
