676 STERNA FORSTEEI, FORSTER's TERN. 



that of the gonys straight and asceudiug ; the gape follows nearly the curve of the 

 culiueu. In shape the bill, in fact, almost rejteats forsteri, and averages the same in 

 length. The tip is broadly straw-yellow ; at the base it appears to have been bright 

 colored (probablj' reddish); a broad band of black intervenes. The whole head is pure 

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

 the pearly color all around. There is a narrow distinct bar of slaty-black on the side 

 of the head, passing through the 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 well as above, is of a uniform lustrous pale pearly, with the following exceptions : 

 The under surfaces of the wings are pure white ; the tail, with its coverts and the 

 rump, are white, but still with an appreciable pearly tint ; the tips, and part of the 

 inner vanes of the secondaries and tertials, are white ; the primaries have the picture 

 common to most Terns, with a white space on the inner webs ; their darker portions 

 are beautifully silvered over with hoary gray, which makes them appear paler than 

 usual ; the shafts are white above and below, except at the extreme tips ; the feet 

 appear to have been reddish or yellowish, certainly of some bright color. 



Dimensions. — Wing, 10.25: tail, 6.50; depth of the fork, 2.75 ; bill, along culmen, 1.50; 

 its depth at base, 0.38 ; length c f gonys, 1.75 ; tarsus, 0.90 ; middle toe and claw, 1.05. 



A specimen belonging to J. P. Giraud, esq., believed to be the original of Audubon's 

 plate and description, agrees minutely with the one from which the foregoing descrip- 

 tion was taken from Buenos Ayres (No. 45801, Mus. Smiths.). In my above-quoted 

 article I discussed the relationshi]is of Audubon's type to S. forstei'i rather elaborately, 

 but not very satisfactorily, in as far as considering it as possibly that species is concerned. 

 I was deceived by the great similarity in its size and proportions to forsteri, and was 

 under the wrong impression that it might gain a black cap. It is clear to me that 

 trudeaui is iierfectly distinct from all other North American species, and that it never 

 gains a black cap ; it is, in fact, one of the most remarkable of all the Terns. I am 

 under the impression that trvdeaid is not its first name, believing it to be one of Vieil- 

 lot's species ; but I cannot now make a determination. 



The species requires comparison with no other, its coloration being peculiar if not 

 unique. In addition to the two specimens above referred to, I have, if my memory be 

 not at fault, seen another in the La Fresnaye collection, now in Boston, labeled with a 

 Vieillotian name. 



The only question is regarding the propriety of introducing the species among North 

 American birds. For myself, I doubt that it was ever actually taken within our limits; 

 but I have no means of disj)roving one author's positive assertion to that effect. 



STERKA FOESTERI, Nutt. 



Forster's Tern. 



Sterna Mrundo, Sw. & Rich., F. B. A. ii, 1831, 412 ; not of authors. 



Sterna forsteri, Nutt., Man. ii. 1834, 274 (foot- note ; based on S. Mrundo, Sw. & Rich.). — 

 Lawr., Ann. Lye. N. Y. v, 18.52, 222.— Bp., Compt. Rend. 1856, 772.— Lawr., B. 

 N. A. 1828, 862.— CoUES, Pr. Phila. Acad. 1862, 544.— Elliot, B. N. A. Introd. 

 (figure of tail).— CouES, Ibis, 1864, 390 (Guatemala).— Salv., Ibis, 1866, 199 

 (the same).— Blas., J. f. O. 1866, 74, 78.— Lawr., Ann. Lye. N. Y. viii, 1866, 299 

 (Long Island).- CouES, Pr. Phila. Acad. 1866, 99 (Arizona).— CouES, Pr. Ess. 

 Inst. V, 1868, 308 (New England).— Scl. & Salv., P. Z. S. 1871, 569 (Guatemala 

 and Brazil).— CouES, Pr. Phila. Acad. 1871, 44 (North Carolina).— Codes, Kev, 

 1872, 321.— Snow, B. Kans. 1873, 12.— Ridgw., A. Lye. N. Y. x, 1874, 391 (Illinois). 



Stei-na havelli, AuD., Orn. Biog. v, 1839, 122, pi. 409, f. 1 ; Syn. 1839, 318; B. Am. viii, 

 1844, 103, pi. 434 (young or winter plumage).— Lawr., B. N. Am. 1858, 861.— 

 CoUES, Pr. Phila. Acad. 1862, 543 (refers it to forsteri). 



GeJochelidon havelli, Bp., Comptes Rendus, 1856, 772. 



Dl\g. S. Steinw Mrttndini similis, sed major, caiidd longiore, magis forficata, alis Ireviorihns, 

 rosiro robustiore, tarsis louyiorihus, i)0(jonio intcrno rcctricis exterioris griseo, exierno alio, 

 gastrwo albido. 



Hal). — North America at large. Middle America. South America to Brazil. Only 

 known to breed in the higher latitudes. 



Adult, spring plumage. — Bill orange-yellow, black for nearly its terminal half, the 

 extreme points of both mandibles yellowish ; robust, deep at the base ; culmen mark- 

 edly declinato-convex, eminence at symphysis well developed; in total length from 

 iV to -f,j of an inch longer than that of S. hiriindo. The black pileum does not extend 

 so far down on the sides of the head as it does in hirundo, barely embracing the eye 

 (the lower lid of which is white), aud leaving a considerably wider white space between 



