LARID^ — LE STRIDING : JlGERS. 737 



all rather narjow and tapering to an acute apex, somewhat rigid and falcate. Secondaries 

 short and inconspicuous ; broad, the tips of the outer ones nearly sijuare, of the inner obliquely 

 incised, the apex being formed by the inner web alone. Tertials long, soft, flexible. Tail 

 moderately long, contained not quite two and a half times in the wing ; very slightly rounded, 

 the graduation being only half an inch. Feathers moderately broad quite to their tips, which 

 are truncated. The central pair project three to four inches. They begin to taper about four 

 inches from their apices, and regularly converge to a very acute tip. Feet rather short and 

 (piite slender ; tarsi as long as the middle toe and claw. Tibia naked half an inch above the 

 joint. The scutellation and reticulation is the same as that already described, but the nails are 

 weaker and less arched, though fully as acute. A decided occipital crest and a calotte. 

 Nuchal region with the feathers acuminate and rigid, with loosened fibrillae. Pileum, occipital 

 crest, and whole upper parts deep brownish-black, with a somewhat slaty tinge, and a slight 

 but appreciable metallic shade ; this color deepening into quite black on the wings and tail. 

 Rhachides of primaries and rectrices whitish, except at their tips ; the inner vanes albescent 

 baso- internally. Chin, throat, sides of head, neck all round, and under parts to the vent, pure 

 white : the feathers of the latero-nuchal region rigid, acuminate, with disconnected fibrillae, 

 light yellow. Under tail-coverts like the upper parts, but somewhat of a fuliginous tint ; the 

 line of demarcation from the white of the abdomen very trenchant. Smaller than No. 765. 

 Wing 12.00-13.00; tarsus 1.75-1.87; bill 1.35-1.50; tail 5.00-6.00, the long feathers up to 

 9.00. Nearly mature: Pileum and latero-nuchal region, and whole upper parts, as in the 

 adult. The under parts white (as in the adult), but clouded everywhere with dusky patches, 

 most marked across breast, on sides, flanks, and under tail-coverts, and leaving the midtUe of 

 the belly and throat nearly pure. Varying degrees of this dusky nubilation approach in some 

 specimens nearly to the uniform dusky below characterized ; in others fade almost into the pure 

 white of the adult, connecting the two states perfectly. The tarsi of the most dusky specimens 

 have small yellow blotches ; the others not. Dusky stage : Wholly deep dusky ; darker and 

 more plumbeous superiorly ; lighter, and with a fuhginous tinge, inferiorly ; the pileum quite 

 black ; the latero-nuchal region yellow ; the remiges and rectrices quite black ; feet black. 

 Immature : Size and general proportions nearly of the adult. Bill and cere perfectly formed ; 

 feet mostly black, but with some yellow blotches. The upper parts unadulterated with any 

 rufous bars ; the deep brownish -black pileum has appeared, and the sides of the neck have 

 obtained their yellow shade, which contrasts conspicuously with the fuliginous back-ground. 

 Evidences of immaturity, however, are found on the under parts, where the dark color is mixed 

 with the illy-defined transverse bars of ochraceous. Rufous is also found at the bend of the 

 wing and on the under wing- and tail-coverts. The primaries are still whitish at the outside, 

 as are also tlie rectrices. The central rectrices project 2i inches, and have the tapering form 

 of those of tlu) adults. Younger : Small size, delicate bill and feet, little projection of the 

 central rectrices, general molUpilose condition of plumage, etc. The rufous of the very young 

 bird, instead of giving way everywhere to dusky, yields to this color only on the upper parts 

 and crown ; on the sides of the head, neck, and the whole under parts, whitish being the pre- 

 dominating color; the continuity of this last being interrupted by indistinctly marked dusky 

 bars. The yellow of the sides of the neck has not yet appeared. There is the same white 

 space on the bases of the wings and tail that exists in the very young. The central tail- 

 feathers only project about 2i inches. Young-of-the-year in Au£>ust: Size considerably less 

 than that of the adult, fijrm every way more delicate. Wings more tlian an inch shorter ; bill 

 and feet much slenderer and weaker. Bill in some specimens light bluish-horn ; in others 

 greenish-olive, the terminal portion brownish-black. Tarsi and greater part of the toes 

 yellow. The bird is everywhere rayed and barred with rufous and browni.sh-black. On the 

 head and neck the rufous has a very light ocliracoous ting3, and is the predominating color, 

 dark only appearing as a delicate line along the shaft of each feather. Proceeding dovra the 



