LABID^ — STEBNIN^ : TEENS. 767 



black, with a narrow white frontal orescent the horns oi which reach over the eyes, the 

 convexity quite to the bill, but cut oflf from the white of the cheeks by a line of black through 

 eye to end of feathers on bUl. Entire upper parts, including tail, pearly-blue, rather dark 

 and of a leaden shade, reaching quite to the black cap, fading on sides of neck and head into 

 the snowy satiny-white of aU. the under parts. Tail-feathers like back, but paler basally 

 and white on their under surfaces, and outer web of the outer feather. Mantle extending to 

 very tips of the tertials and secondaries, but inner webs of these feathers nearly white toward 

 the base. Shafts of first two primaries black on top, white underneath, the webs black, the 

 inner with a white space, distinctly outlined from the black, not reaching ends of the feathers ; 

 other primaries like back, but darker plumbeous, fading to white on their inner borders. 

 Feet orange-yellow, claws black. Adult in winter : Bill black ; feet duU yellowish. Fore- 

 head and lores white ; crown white, with black shaft-lines ; occiput and nape blackish, 

 sending forward a band through eye. Mantle darker than in summer, and more restricted, 

 leaving hind-neck white; a band of grayish-black along fore-arm, and whole edge of the 

 wing of this color. Most of the primaries blackish, without silvering. Young of first winter : 

 Similar, forehead not pure white, nor hind-head quite blackish, mautle varied with lighter 

 tips of most of the feathers ; tail with traces of dark spots. Young in August : Bill brownish- 

 black, pale at base below. Forehead mostly white ; crown and hind-head varied with white 

 and brownish-black, the latter color especially forming an auricular patch. Pearl-gray 

 mantle of the adults appearing, but interrupted with brown hastate or crescentic spots, one 

 or more on each feather, mottling the whole upper parts. Primaries grayish-black, growing 

 lighter from first to last, margined on inner webs with white, broadly and briefly on outer 

 primaries, more narrowly and lengthily on successive ones ; outer web of first primary, and 

 shafts of aU on upper side, black. Tail merely emarginate, without elongation of outer 

 feathers ; pearly-blue, shading towards the ends of the feathers to dusky-gray, the tips white.. 

 Whole under parts pure white. A pretty little " sea-swallow," inhabiting temperate N. Am., 

 especially along the Atlantic coast of the U. S., but also on larger inland waters ; Pacific 

 side to Cahfomia ; South into the Antilles and Middle America ; very intimately related to 

 the S. Am. siiperciUaris and European minuta. Eggs dropped on bare dry sand of beaches, 

 or in a little shelly depression, 1, 2, or 3 in number, 1.20 to 1.30 by 0.99; ground color 

 varying from pale clear greenish to duU pale drab, speckled aU over with small splashes, 

 irregular spots and dots of several shades of clear brown, with paler and more lilaceous 

 sheU-spots; the markings often evenly distributed, more frequently tending to wreathe at 

 or around the larger end, the point often free from marks or with only a few dots. 

 803. S. trudeau'i. (To Dr. James Trudean.) Trudeau's Tern. White-headed Tern. Size 

 and proportions nearly as in S. forsteri, the bill especially of same size and shape. Coloration 

 very diflferent, unique in the subfamily. Adult : BUI straw-yellow at end, apparently bright 

 colored, probably reddish, at base, with a broad black intervening band. The whole head pure 

 white, including all the parts about the base of the bUl ; this deepens insensibly into the pearly 

 color all around. A narrow distinct bar of slaty-black on side of head, passing through eye 

 from a point just in advance of the auriculars, where the fascia widens and bends down a little. 

 All the rest of the plumage, below as weU as above, of a uniform lustrous pale pearly, with 

 the following exceptions : Under surfaces of wings pure white ; tail, with its coverts and the 

 rump, white, still with an appreciable pearly tint ; tips, and part of inner vanes of secondaries 

 and tertials, white ; primaries with the picture common to most terns, with a white space on 

 the inner webs ; their darker portions beautifully silvered over with hoary gray, which makes 

 them appear paler than usual; shafts white above and below, except at extreme tips ; feet 

 appear to have been reddish or yellowish, certainly of some bright color. Wing 10.25 ; tail 

 6.50; depth of the fork 2.75; biU along culmen 1.50; its depth at base 0.38 ; length of gonys 

 1.75; tarsus 0.90; middle toe and claw 1.05. A rare and remarkable species belonging to 



