1014 SYSTEMATIC SYNOPSIS. —LONGIPENNES. 



fresh; outer wel) of ]st blackish; inner webs of all white for more than half their breadth, 

 this white stripe broadest on the first, toward the base of which it occupies the whole web, 

 and on all of them continued to and usually around the very tips ; shafts of all white both sides 

 nearly to end. Adult in winter : Bill dull black, with yellowish tij) and brown base. Fore- 

 head and cheeks white; crown, hind-head, nape, and sides of head, brownish-black, mixed 

 with white on vertex. No rosy tint. Lesser wing-coverts brownish. Tail without much 

 elongation or forking, and pearly like the back. Young, newly fledged : Bill small, slender, 

 blackish, hardly 1.10. Wings like those of adults. Tail merely forked an inch or so, pearly- 

 blue on outer webs, almost white on inner, with subterminal edging of blackish. Mantle light 

 pearly-blue, variegated with a delicate mottling of black and bufi", the black chiefly in narrow 

 zig-zag cross-bars, broken by the fawn-color; on the wings the variegation in larger pattern, 

 the feathers mostly black with yellowish borders. Forehead and cheeks light grayish-brown, 

 resolved on crown and hind-head into streaks of blackish and tawny, lost in blackish on nape. 

 A silvery white spot before and above eye ; eye surrounded by black. A band of black along 

 edge of forearm, where some of the feathers have yellowish tips. Under parts pure white, a 

 little obscured with gray on the breast. Adult: Length 14.00-15.00; extent about 30.00; 

 wing 9.25-9.75; tail 7.00-8.00, forked 3.50-4..50; bill along culmen 1.50; height at base 0.35; 

 gonys 1.00; mandibular rami 0.75; tibife bare 0.40; tarsus 0.85; middle toe and claw 1.00. 

 This exquisite species inhabits Europe, Asia, Africa, etc.; in North America it occurs along 

 the whole coast of the Atlantic and Gulf States, in various West India Islands, and Central 

 America; breeds nearly throughout its U. S. range, wintering extralimital. It is a beach bird, 

 nesting on the sand of the seashore; eggs 2-3, about 1.65 X 1-20, indistinguishable from 

 those of several related species, especially the Arctic Tern ; said to average rather lighter 

 colored, with smaller spots. 



S. aleu'tiea. (Of the Aleutian Isles. Fig. 098.) Aleutian Tern. Form of ^S^ema proper ; 

 tail deeply forked, with long streamers as mforsteri, etc. Coloration darker than that of any 

 of the foregoing species, approaching that of the section Onychoprion, and presenting a white 

 frontal lunule as in Sternula and Onychoprion. Adult (J 9 > in 

 summer: Bill and feet black. Crown and nape black; a large 

 white frontal crescent, the horns of which reach over the eyes, and 

 the convexity of which extends into the nasal fossae- The black 

 vertex sends through the eye a band that crosses the cheek and 

 Fig. C98. — Aleutian Tern, much reaches almost to the point of greatest extension of feathers on 

 '® "''® ■ the bill. Chin and side of head bordering this vitta below pure 



white, presently deepening insensibly into the hue of the under parts. Tail and its coverts 

 pure white — no pearly wash on any of the feathers. Mantle dark pearl-gray, with a leaden 

 hue, diff'erent from the clear pearly of paradisrea, etc., yet not of the smoky cast of ancestheta, 

 etc. — a tint intermediate between these, difficult to name satisfactorily ; it extends on the neck 

 behind to the black of the nape without intervention of white. All under parts, from the white 

 chin to under tail-coverts, paler and more decidedly pearly than the mantle, nearly as in full- 

 plumaged paradiscea, yet grayer. Under wing-coverts, edge of wing, and shafts of primaries, 

 pure white. Primaries blackish, with the usual silvery hoariness, and with large white spaces 

 on inner webs ; this space on the 1st primary occupies at base the whole width of the web, but 

 grows narrower and ends about 1.00 from the tip, which is wholly blackish, this color running 

 down as a narrow margin for 2.00 or more. On other primaries successively this white space 

 diminishes, and is also less distinctly defined. Secondaries like the back, but most of the inner 

 web of all white, and a narrow oblique touch of white on outer web near its end, forming a bar 

 across the wing when closed. Length 13.50-15.00; wing 9.75-10.75; tail 6.50-7.00, forked 

 2.40-3.75; bill along culmen 1.40; along gape 1.70; height at base 0.30; length of gonys 

 0.80; tarsus 0.60-0.75; middle toe alone 0.80; its claw nearly 0.30. Alaska and Aleutian 



