Head rather small, oblong, compressed. Neck of moderate length. Body rather slender. Feet rather long, slender; tibia bare a third part of its length; tarsus compressed behind, covered anteriorly and posteriorly with numerous scutella, which scarcely leave any intermediate space; hind toe extremely small; the rest of moderate length, slender, the fourth slightly longer than the second, the third longest; all free, there being only a very slight rudimentary web between the third and fourth, flat beneath, slightly marginate with rather pointed scales. Claws small, slightly arched, compressed, rather acute, that of the third toe much larger, with the inner edge dilated.
Plumage very soft, blended on the lower parts, the feathers distinct above. Wings very long, pointed; primaries tapering, obtuse, the first longest, the second almost equal, the rest rapidly graduated; outer secondaries incurved, narrow, obliquely sinuate at the end of the outer web, the inner rounded and extending beyond the outer; inner secondaries very narrow, tapering to a point, reaching, when the wing is closed, to about half an inch from its tip. Tail of moderate length, nearly even, but with the two middle feathers exceeding the rest, the number of feathers twelve.
Bill and feet dusky. Iris brown. The general colour of the upper parts is brownish-black, each feather edged with yellowish-grey, the scapulars with light red. Wing-coverts greyish-brown, the shaft black; primary and secondary coverts tipped with white; quills brownish-grey, darker towards the tips, the inner primaries and outer secondaries more or less edged and tipped with white; the tail-coverts white with a dusky spot, excepting the two central, which are blackish, with a few greyish-white markings. Tail-feathers light grey, the two middle brownish-black towards the end. Sides of the head, fore neck, anterior part of breast and sides greyish-white, with small lanceolate central brownish-black spots; the rest of the lower parts white.
Length to end of tail 7 1/12 inches, to end of wings 7 7/12, to end of claws 7 9/12; extent of wings 14 3/4, bill along the back 10 1/2/12, along the edge of lower mandible 11/12; wing from flexure 4 10 1/2/12; tail 2 2/12; tarsus 11/12; middle toe 9 1/2/12, its claw 2/12.
Adult Female in winter. Plate CCLXXVIII. Fig. 2.
The Female is similar to the male, but a little smaller.
In some individuals, about six of the middle tail-coverts are black, the lateral barred with white and dusky.
THE SANDWICH TERN.
Sterna cantiaca, Gmel.
PLATE CCLXXIX. Adult and Young.
On the 26th of May 1832, while sailing along the Florida Keys in Mr Thruston’s barge, accompanied by his worthy pilot and my assistant, I observed a large flock of Terns, which, from their size and other circumstances, I would have pronounced to be Marsh Terns, had not the difference in their manner of flight convinced me that they were of a species hitherto unknown to me. The pleasure which one feels on such an occasion cannot easily be described, and all that it is necessary for me to say on the subject at present is, that I begged to be rowed to them as quickly as possible. A nod and a wink from the pilot satisfied me that no time should be lost, and in a few minutes all the guns on board were in requisition. The birds fell around us; but as those that had not been injured remained hovering over their dead and dying companions, we continued to shoot until we procured a very considerable number. On examining the first individual picked up from the water, I perceived from the yellow point of its bill that it was different from any that I had previously seen, and accordingly shouted “A prize! a prize! a new bird to the American Fauna!” And so it was, good Reader, for no person before had found the Sandwich Tern on any part of our coast. A large basket was filled with them, and we pursued our course. On opening several individuals, I found in the females eggs nearly ready for being laid. The males, too, manifested the usual symptoms of increased action in the organs distinctive of the sex. I felt a great desire to discover their breeding grounds, which I had the pleasure of doing in a few days after.