THE ARCTIC TERN. \\\ 



extremely short, slender, roundish, covered anteriorly with small scutella, 

 laterally and behind with reticular scales; toes very small, slender, the first 

 extremely small, the third longest, the fourth nearly as long, the second 

 much shorter, all scutellate above, the anterior connected by reticulated webs 

 having a concave margin; claws arched, compressed, acute, that of hind toe 

 smallest, of middle toe by much the largest, and having the inner edge thin 

 and dilated. 



Plumage soft, close, blended, very short on the fore part of the head; the 

 feathers in general broad and rounded. Wings very long, narrow and 

 pointed; primary quills tapering, slightly curved inwards, the first longest, 

 the rest rapidly graduated; secondary short, broad, incurved, rounded, the 

 inner more tapering. Tail long, very deeply forked, of twelve feathers, of 

 which the outer are tapering, the middle short and rounded. 



Bill, mouth, and feet vermilion tinged with carmine. Iris brown. The 

 upper part of the head and elongated occipital feathers greenish-black; the 

 sides of the head and chin white; the upper parts pale greyish-blue, the rump 

 lighter, the tail white, excepting the outer webs of the two lateral feathers 

 which are dusky-grey; primaries dusky towards the ends, the two outer with 

 their outer webs blackish, all with the greater part of the inner web white; 

 secondaries tipped with white. Neck, breast and sides pale greyish-blue, 

 like the upper parts, but lighter; abdomen, under tail-coverts, and lower 

 surfaces of wings and tail white. 



Length to end of tail 15^ inches, to end of wings 13^, to end of claws 

 9f; extent of wings 32; wing from flexure 10^; tail to end of shortest 

 feathers 3^, to end of longest 7^; bill along the ridge H, along the edge of 

 lower mandible lyf ; tarsus T 8 ? ; middle toe \\, its claw ff . Weight 2f oz. 



