573 



the same manner, and insects, which it catches on 

 the wing; and a party of these birds may occasionally 

 be seen on a summer evening skimming above the 

 meadows in pursuit of winged insects.* 



As I said before, the Arctic Tern is much like the 

 Common Tern, more especially in its immature 

 plumage ; but it may at any age be distinguished 

 from that bird by the shortness of its tarsus, which 

 in the present species only measures six lines, and in 

 the Common Tern is as much as eight lines and a 

 half: this appears to be nearly the only distinction 

 between the immature birds, unless the dark mark 

 along the shoulder of the wing, which I before men- 

 tioned when describing the Common Tern, should 

 turn out to be a good distinction. In more mature 

 birds the under parts are darker than in the Common 

 Tern, being almost the same colour as the back. 

 The following description of the adult bird is taken 

 from a specimen shot at Stolford during the last 

 week in April: the bill is coral-red; hides very 

 dark brown ; the whole of the upper part of the 

 head as far down as to the eye, and the nape of the 

 neck are glossy black ; the back, scapulars and wing- 

 coverts are uniform gull-grey; the rump and tail- 

 coverts are white ; the primary quills are dusky grey, 

 white on the inner part of the inner web, and the 

 shafts are white ; the tail is much forked, the two 



* ' Zoologist ' for 1865, p. 9766. 



