LARIDJS — STERNIN^: TERNS, SEA SWALLOWS. ' 1003 



tall's Tern. Adult (J 9 > ii summer : Crown and long occipital crest glossy greenish-black, 

 extending to lower border of eye, leaving only a very narrow line of white along edge of feath- 

 ers on side of upper mandible. Neck all round and under parts white. Mantle Hglit pearl- 

 blue, this color e.xtondiug over rump and tail ; tail-feathers deepest colored at their tips, fading 

 into nearly pure white toward their bases, on that portion of each which is covered with the 

 next one ; color of mantle also extending to tips of inner secondaries. Primaries grayish -black, 

 deepest on the outer vane of the 1st, but this color so heavily silvered as to appear much 

 lighter. All the primaries have pale yellowish shafts ; on their inner webs is a space of white 

 which on the 1st is largest, purest, and extends farthest, is distinctly defined from the black, 

 and has not a margin of black along its inner border, except just at its apex. The amount of 

 white diminishes in length and breadth with each successive primary, until on the last one it is 

 inconspicuous. Bill black, with or without a minute yellowish tip; legs and feet greenish- 

 black ; iris brown. In winter : The black cap restricted chiefly to the hind head and nape, on 

 sides of head reaching forward to eye; sometimes extinct, except in dusky eye-stripe and spot 

 before eye, when whole head otherwise white. Young : Bill blackish-brown, pale at base 

 below; feet dull brownish. Upper parts pearl-blue, interrupted by numerous crescentic or 

 hastate spots of dull brownish, one on each feather, the extreme tip of which is whitish. A 

 brownish-black bar along lesser wing-coverts. Forehead and most of crown white, with dark 

 shaft-lines, increasing to exclude white on hind head and nape; blackish spot before and be- 

 hind eye. Neck all around, upper tail-coverts, and whole under parts, white. Tail-feathers 

 whitening at ends, each with a dusky space. Fledglings chiefly buff' and brown above, before 

 any pearly-blue appears; nestlings in down grayish-buff above, streaked, spotted, and mottled 

 with dusky; under parts white, tinged with gray to some extent. Length 13.00-15.00; ex- 

 tent 33.00-37.00; wing 11.75-12.25; tail 5.50, forked 1.20-1.75; bill 1.40; along gape 2.00; 

 its height at base 0.45; tibife naked 0..50; tarsus (average) 1.30; middle toe and claw 1.10: 

 hind toe and claw 0.40. Nearly cosmop(ditan ; Europe, Asia, Africa, Australia; in North 

 America, chiefly from Texas to New England ; not abundant anywhere, and rare inland ; S. 

 on Atlantic coast to Argentina, and on Pacific coast of southern Mexico and Central America; 

 breeds in the U. S. north to New Jersey, on .sandy shores, and also in marshes, like the 

 lilack Tern ; eggs usually 3, laid on bn^ken-down reeds or grasses, 1.75 X 1-30, olivaceous- 

 buff", largely and irregularly splashed with stone-gray, umber-brown and blackish, especially 

 about the greater end, but very variable, like all Terns' eggs. S. ((?.) anglica of former eili- 

 tions of the Key. Among the numerous names of tiiis Tern the first is no doubt S. niloticn of 

 Ilassehiuisl's Iter or Reise, 1757 and 17()2 : see Gray's Hand-list, iii, 1871, p. 11!), and Auk, 

 1684, J). 3ti4. G. nilotica, A. 0. U. Lists, 188G and 1895, No. 63. 



STER'NA. (Latinized by Turner, 1544, from English stern, starn, or ieni.) Terns. Sea 

 Swallows. Form typical of the subfamily. Nostrils sub-basal. Frontal antia; i)rominent. 

 Tail more or less forked. Tarsus not shorter than middle toe without claw. Lateral toes 

 much sliortrr tlian middle. Webs moderately incised. Under parts of adult white, or like 

 back. Upper parts of most species with pearly-blue mantle and black cap. Tiiis is much the 

 largest genus of Sternince, containing over 30 species, or more tlian lialf of the subfamily. Tliey 

 dirter a good deal among themselves in minor details of fortn and coloration, and couseiiuently 

 represent several subgenera. Those of North America may be readily determined by the 

 following : 



Analysis of Siihijenera ami Species. 



Of large to larftest size ; winfc ovpr 1_>.0<I ; bin oviT 2 fK). Head crested. Fcpt black . Muntle prnrly C;ii> bUok. 

 Tail contaiiipd about :$ times in leiiKtli of wiiig, lightly forkol PriiiiaricH with.mt white spatv.s on iiinor webs. 

 Crest HliKlit. (Thalasseus.) 



Bin red, stout. Wing ir,.(K( ; tail .''..'.(); biU nearly .TOO raspia 



Tail contained about twice in length of wing, forked about Irilf its length. Prim iries with whiti- sjuu-es on iuuer 

 webs. Crest well marked. (Actochkliix>n.) 



