758 



SYSTEM A TIC SYNOPSIS. — L ONGIPENNES — GA VI.E. 



Tibiae bare about 0.75 ; tarsus 1.75, rather exceeding middle toe and claw, the scutella iu 

 ft-ont replaced by polygonal scales similar to but larger than those on its sides, which are 

 rough ; hind toe extremely small ; outer lateral nearly as long as middle toe and claw, which 

 is 1.G5. Bill dark vermilion red, growing lighter and somewhat " diaphanous " toward the 

 tip. Pileum and occipital crest glossy greenish-black, extending to below the lower level of 

 the eyes, and occupying the termination of the feathers on the side of the mandible to the 



\ 





Fig. 512. —Caspian Tern, g nat. size. (From Brehiii.) 

 exclusion of the white ; lower eyelid white, forming a noticeable spot on the greenish ; a 

 white streak along sides of upper mandible, not extending to the end of the feathers. Mantle 

 pearl-blue, the line of demarcation between it and the white rather indefinite, both on nape 

 and rump ; most of the tail-feathers, and especially the central ones, retaining a more or less 

 pearly tint. Shafts of the primaries yeUowish-white ; primaries grayish -black, but, when 

 new, so heavily silvered over as to appear of a light hoary gray, especially on their superior 

 aspects. On the inner web of all there is a central light field ; this is very narrow, even on 

 the first primary, although it runs for some considerable distance, and on the others it rapidly 

 grows less ; and it has no trenchant line of di^^sion on any of the primaries from the darker 

 portions of the feather. Whole inner web of secondaries pure white, outer pearl-blue. Legs 

 and feet black. Adult, winter plumage : Chiefly distinguished by a diminution in the bright- 

 ness of the biU, and by a change in the character of the pileum. The vermilion is replaced 

 by light orange-red, growing stiU yellower toward the tip of the bill and along the tomia. 



