160 BRITISH BIRDS, THEIR EGGS AND NESTS. 
light yellowish stone-colour, spotted and speckled with dark-grey 
and dark-brown. 
293. COMMON TERN—(Sterna hirundo). 
Sea Swallow, Tarney or Pictarney, Tarrock, Pirr, Gull-teazer, 
&e.—Although distiguished by the epithet of Common, this Tern 
is really not much more numerous, and in that sense common, 
than one or two other species with which it customarily consorts. 
It is very generally diffused however, and in that sense 7s common. 
It usually builds on the ground in marshy localities near large 
sheets of water, or on islands low and flat not far from the sea. 
Sometimes, though more rarely, it builds upon low rocks or 
slightly elevated sand-banks. ‘They lay two or three eggs, and 
are exceedingly and noisily restless and uneasy when they, or 
especially their young, are too nearly approached. Their eggs 
vary a good deal, but most of them are of a medium stone-colour, 
blotched and spotted with ash-grey and dark red-brown. The 
buoyancy and power of flight exhibited by these birds is very 
observable —Fig. 3, plate XI. 
ARCTIC TERN—(Sterna arctica). 
This Tern, until a comparatively recent period, was confounded 
with the Common Tern, but a clear specific difference was pointed 
out by M. Temminck, and it is now acknowledged that, in many 
of the more northerly localities especially, it is a much more 
numerous species than the Common Tern. It breeds plentifully 
in Shetland, Orkney and some parts of the Hebrides, and in great 
numbers on Coquet Island and one or more of the Farnes. It 
lays two or three eggs, which are exceedingly like those of the 
Common Tern, and vary in the same proportion. Some have a 
greenish shade, and others rather a pronounced buff, spotted and 
