716 EHYNCllOPS NIGRA, BLACK SKIMMER. 



obsolete toward the joint, and have exceedingly oblique margins. Laterally and pos- 

 teriorly there are plates, small, regular, smooth, of a polyhedral (mostly hexuKoual) 

 shape, largest and flattest on the sides of the tarsus, smaller and more roughened 

 behind and on the joint. The toes superiorly are delended, as is the tarsus, by scutella, 

 the webs by small reticulated plates; on the inferior surfaces of both the plates are 

 nearly obsolete. The middle and outer toes are of much the same length, the inner 

 much shorter, the tip of its claw reaching the base of the middle claw. The hallux is 

 of moderate length for this family ; its claw short, stout, blunt, little curved. The 

 anterior claws are all long, slender, depressed, moderately arched, rather acute, the 

 inner edges of all dilated, that of the middle one most so. The interdigital membranes 

 are of the ordinary width and amount of emuryination. The feet in life are carmine- 

 red, in the dried state dull yellowish, with a tinge of pink. 



The wings are excessively long and powerful. The primaries are broad, their 

 rhachidea strong, outer five or six of a somewhat falcate shape, narrowing rather sud- 

 denly when near the tip to their only moderately acute and r.ather rounded apices. 

 'J'he secondaries are short, broad to their very tips, which are rounded, with a very 

 slight amount of excision of the extremities of their outer webs. The superior surface 

 of the wings is glossy black, like the back ; their inferior aspect, except a narrow lino 

 along their metacarpal edge, white; this color deepening toward the ends of the pri- 

 maries, first into grayish, and then into blackish. The first six primaries are concolor, 

 black, pure and ticep on their outer web, lighter and of a brownish tinge on their 

 inner; their rhachides black. The inner lour primaries are brown; their inner webs, 

 and the tips of both webs, white. The secondaries are white, with a space of dark 

 brown occupying nearly the whole of their outer and a small part of their inner 

 webs. The amount of brown is least on the outjr ones ; increases on each leather suc- 

 cessively, till the last four secondaries and the tertials arc brownish-black, except a 

 narrow apical margin. 



The tail is of moderate length, being contained rather less than three times in the 

 wing. It is moderately emarginate. The feathers are rather narrow, the central pair 

 rounded at their tips, the lateral ones converging to a very obtuse point. The upper 

 tail-coverts are short, being scarcely half the length of the tail; the inferior oneH, how- 

 ever, reach within a short distance of the tips of the, central rectrices. The tail and 

 its under coverts are white, the inner webs of all the rectrices more or less obscured 

 witli dark brown, deepest on the central pair. The superior coverts are Ijlack like the 

 hack, except the outer row on each side, which are white. 



Crown of the head, its sides just below th(! eyes, the back of the neck, and whole 

 npper parts, pure glossy black. The forehead, cheeks, sides of the head bcjlow the 

 eye, sides of the neck, and whole under parts, pure white ; tinged in life, during the 

 nuptial season, with rosy. 



Vimensions. — Length (of males), 20; extent of wings, 49; wing from flexure, 16 to 

 16..50; from apex of longest secondary to tip of first primary, 6; tail, •)S)(J to 6; depth 

 of fork, 1 to 1.25; upper mandible along culmen, 3; along g.ape, 4; height opposite 

 middle of nostrils, 0.60; width at same place, 0.4r>; length of nasal foss.a, 0.75; of 

 nostrils, 0.40 ; under mandible along gonys, 3.75; along fused tomia, 3.60; along gape, 

 4.50 ; from feathers on its side to tip, 4.10 ; itsdepth at deepest part, just anterior to 

 beginning of symphysis, 0.60 ; dei)th ni tip, about 0.25 ; length of longest oblique 

 stria, about 0.40 ; tibiaj bare, 1.10; tarsus, 1.45; middle toe and claw, 1.30; outer toe 

 and claw, 1.20 ; inner toe and claw, 0.95 ; hallux and claw, 0.35. 



The preceding description was taken from a large and very perfect siiecimen obtainc;d 

 in Florida. The dimensions are perhaps somewhat greater than the average of exam- 

 ples, but not more so than is frequently found to be the case. Individuals vary 

 greatly in size, many apparently equally adult examples being much smaller than the 

 one whose dimensions I have just given. I believe that Audubon is quite correct in 

 saying that the females are smaller than the males. They will not average probably 

 more than 16 or 17 inches in length, by about 42 in extent of wings, as he has said. 

 I have also found the bills to be much thinner, lighter, and weaker. In colors the 

 sexes hardly differ notably. 



Toung-of-the-year. — Bill smaller th.an in the adult, thinner, weaker, its ridges less 

 sharply defined, and the two mandibles of less unequal length. General proportions 

 less than in adult. Bill brownish-black for three-fourths of its length, fading into dull 

 horn-color just at its tip, lightening into more or less intense flesh color, or light red- 

 dish, toward the base. The strite on the sides of the lower mandible are as numerous as, 

 but much less distinct than, in the adult. Tail shorter and less deeply emarginate. 

 Legs and feet dull light reddish. Entire upper parts a rather light grayish-brown, 

 deepest on the wing-coverts and tertials ; each feather with a tolerably broad margin 

 and tip of white, broadest and most conspicuous on the wing-coverts and tertials. 

 Forehead, sides of the head below the eyes, the neck all round, the edge of the fore- 

 arm, inferior surfaces of the wings, and whole under parts, white. Primaries almost 

 exactly as in the adults, except that the innermost have more white, and there is a 



