GREAT TERN. 155 



of rivers, and are occasionally seen about all our nume- 

 rous ponds, lakes, and rivers, most usually near the 

 close of the summer. 



This species inhabits Europe as high as Spitzbergen ; 

 is found on the arctic coasts of Siberia and Kamtschatka, 

 and also on our own continent as far north as Hudson's 

 Bay. In New England, it is called by some the mackerel 

 gull. It retires from all these places, at the approach 

 of winter, to more congenial seas and seasons. 



The great tern is fifteen inches long, and thirty 

 inches in extent ; bill, reddish yellow, sometimes bril- 

 liant crimson, slightly angular on the lower mandible, 

 and tipt with black ; whole upper part of the head, 

 black, extending to a point half way down the neck 

 behind, and including the eyes ; sides of the neck and 

 whole lower parts, pure white; wing-quills, hoary, as 

 if bleached by the weather, long and pointed; whole 

 back, scapulars, and wing, bluish white, or very pale 

 lead colour; rump and tail-coverts, white ; tail, long, and 

 greatly forked, the exterior feathers being three inches 

 longer than the adjoining ones, the rest shortening 

 gradually for an inch and a half to the middle ones, 

 the whole of a pale lead colour ; the outer edge of the 

 exterior ones, black; legs and webbed feet, brilliant 

 red lead ; membranes of the feet, deeply scalloped ; 

 claws, large and black, middle one the largest. The 

 primary quill-feathers are generally dark on their inner 

 edges. The female differs in having the two exterior 

 feathers f the tail considerably shorter. The voice of 

 these birds is like the harsh jarring of an opening 

 door, rusted on its hinges. The bone of the skull is 

 remarkably thick and strong, as also the membrane 

 that surrounds the brain ; in this respect resembling the 

 woodpecker's. In both, this provision is doubtless 

 intended to enable the birds to support, without injury, 

 the violent concussions caused by the plunging of the 

 one, and the chiselling of the other. 



