797. 
762 SYSTEMATIC SYNOPSIS. — LONGIPENNES--—GAVLZ. 
tip of bill less in extent and intensity of color ; t white, either pure or speckled with black ; 
crown variegated with black and white, the former color consisting of small, narrow, distinct 
streaks along the shaft of each feather; but the long occipital crest, which does not entirely 
disappear at this season, usually remains of an unmixed brownish-black. Lateral tail-feathers 
shorter than in summer. Young-of-the-year: Considerably smaller than the adult, as is usual 
in this subfamily, the wing being a full half-inch shorter. Bill shorter and weaker, and 
without sharply-defined angles and ridges, brownish-black, the extreme point only yellow- 
ish. Crown, front, and occiput brownish-black, variegated with white; white touches very 
small on the forehead. Upper parts as in adult, but everywhere marked with irregularly- 
shaped but well-defined spots and transverse bars of brownish-black. No well-formed occipital 
crest until after the first moult. Primaries like those of adult. The tail, however, is very different. 
The feathers for three-fourths their length are of the color of the back; this color gradually 
deepens, until toward the tips it becomes brownish-black, each feather having a terminal irreg- 
ular edge left whitish. Tail simply deeply emarginate, the outer feathers being but slightly 
longer than the second. A fine species, alone among the large terns, with its black yellow- 
tipped bill, of wide distribution in both Hemispheres; in N. Am. observed along Atlantic 
coast, New England to Texas; both coasts of C. Am.; 8. Am. Eggs 2-3, dropped on the dry 
sand; 2.10 x 1.40; rather pointed, yellowish-drab, most irregularly spotted with dark brown 
and reddish-brown, with lilac shell-spots. Breeds in large colonies, like most terns. 
S. hirun’do. (Lat. hirundo, a swallow.) Common TERN. WILSON’S TERN. SEA 
Swautow. Adult, summer plumage: Bill as long as head, about equalling tarsus and middle 
toe without claw, of moderate robustness ; height at base contained a little more than five 
times in length of culmen; gonys as long as rami, measured from feathers on side of mandible 
to eminentia symphysis, which latter is but slightly marked; bright coral, or light vermilion, 
on basal half or rather more, the remainder black, except the extreme tips, which are yellow- 
ish. Pileum lustrous velvety-black, with tinge of glossy-green ; it extends to lower level of 
eyes, but leaves the lower lids white, and it is so broad on the lores that the white line of 
feathers along side of mandible hardly reaches to their extremity. Whole upper parts pearl- 
blue, this color commencing insensibly on back of neck, deepening on dorsum, and extending 
quite undiluted almost to the extreme apices of the tertials; ending abruptly and distinctly 
on rump, the upper tail-coverts being pure white. Under parts of a considerably lighter 
shade of the color of the back. On the throat, toward the chin and along the borders of the 
black pileum, it fades into nearly or quite pure white, as it does also on the lower tail-coverts 
and the cireumanal region; inferior surfaces of wings and axillary feathers pure white. 
Shafts of all the primaries white, deepening into blackish toward their apices. Outer web of 
first primary black, with scarcely any hoarimess. The first four or five primaries are grayish- 
black, with a very strong silvery hoariness ; their inner webs with a space of white along their 
inner margins. This space on the first primary at the base occupies the whole web, becomes 
narrower as it ascends, and ends, or becomes a mere line, about an inch from the apex of the 
quill. On the other primaries it is of less extent, and runs up along the centre of the shaft a 
little further than on the edge. On the innermost primaries, again, it is very narrow, but 
forms an entire margin to the inner webs, running quite to their tips. The inner primaries 
have searcely any grayish-black, but are rather of the color of the mantle. Secondaries mostly 
pure white, but toward their ends have a space grayish-blue of about equal extent on both 
webs. Tail moderately elongated and forked, contained about 13 times in the wing; the 
folded wings reach one to two inches beyond it; central feathers broad to their evenly rounded 
tips; the lateral ones suecessively narrower, more tapering and acute; their owter webs light 
pearl-gray (very like the back), their inner webs nearly pure white. The external pair, how- 
ever, are on most of their inner webs, especially terminally, grayish-blue, while their outer 
webs are dark grayish-black. Legs and feet light coral-red. Dimensions: length (average) 
