702 STERNA AN^STHETA, BRIDLED TERN. 



black. The frontal white lunula is narrower than fuTiffinom, of about the same width 

 as in lunula, and, as in that species, extends some distance behiud the eye, which is not 

 the case in fulitjinosa. The black pilcum is, on the nape, sharply defined against ashy- 

 white, which, as it proceeds backward, gradually deepens iut-o the cinereous-brown, 

 which is the prevailing color of the upper parts, the wings, and especially the prima- 

 ries, are darker than the rest of the upper parts, aud have scarcely a shade of cniereous; 

 the tail, with its coverts, however, is much lighter and more ashy, approaching the 

 nape in color. The primaries, as in lunata, have well-defined, pure white spaces run- 

 ning for a considerable distance from their bases along the inner web, while in 

 fuliginosa the inner webs are simply grayish-brown, with no well-marked pictura. A 

 large part of the inner webs of the secondaries and tertials are also white. All the 

 under wing-coverts are pure white. The central tiil feathers are, as already described, 

 brownish-ashy, concolor with their coverts. The lateral on«s have much white toward 

 their bases, especially on the inner webs, and this increases on each feather success- 

 ively to such an extent that the next to the outer one is wholly white except a small 

 space at its tip, while the outermost is entirely white. In fuliginosa only the outer- 

 most one is white. (Compare descriptions.) The shafts of the primaries are brownish- 

 black above, white beneath ; of the rectrices, dark along the cinereous, and white 

 along other portions of the feathers. Below the bird is entirely pure white. 



Z)!n!CHsions.— Length, 14 to 15 inches; wing, from the carpus, 10.50 ; tail,6to7;* bill, 

 1.40 to 1.60 ; height at base, 0.35 to 0.40 ; width, slightly less ; tarsus, 0.85 ; middle toe 

 the same, with the claw 1.20; outer toe and claw, 1.00; inner, 0.75. These measure- 

 ments, it will be seen, are intermediate between those of fuliginosa and lunata. 



Immature plumage.— k specimen (No. 11394, Nicaragua, Oct., 1858, Dr. Caldwell), 

 probably a bird of the first year, is slightly smaller, as would have been expected, but 

 in form is the same. The differences in the plumage are : The black of the pileum is 

 imjierfect, largely mixed with white on the vertex, so that it fades insensibly into the 

 whit« of the lunula, which latter is thus obscured. The black frenum is corre. pond- 

 ingly imperfect. The upper parts are paler and grayer, some of the feathers being 

 margined with whitish. The lateral rectrices are not wholly white. The under parts 

 are pure white, as before. This is probably not the youngest plumage (of which I 

 have yet to see specimens, that may perhaps be all dusky, white-spotted, \\]i.e. fuliginosa), 

 but rather represents a plumage that closely resembles, if it be not identical with, the 

 ordinary winter plumage of the adult. 



This bird scarcely requires comparison with fuliginosa. The light ashy-white nape 

 and hind neck ; the black cap contrasting vrith the color of the back, besides being 

 separated by the whitish cervix ; the wings darker than the back ; the amount of white 

 on the tail ; the narrowness and length of the frontal lunule ; the differently-shaped 

 bill and the smaller size, at once distinguish it. The species in fact comes nearer lunata, 

 Peale, a rather dark-colored species, in which the crown and back are also conspicu- 

 ously different from each other in color. S. lunata, however, is a smaller bird, with a 

 grayish-plumbeous mantle, more nearly as in typical Sternw. It is well described aud 

 figured by Mr. Cassin in the Ornithology of the United States Exploring Expedition. ■ 



Synonymy. — In 1864 I reached, by some devious path 1 do not now remember, the 

 conclusion that panaycnsis, Gm. (or panaya. Lath.), were rather referable to fuliginosa 

 than to this species ; but upon reconsideration of the subject, I see that the less said on 

 this score the better. It was upon this erroneous consideration that I proposed the 

 term discolor, not that I desired to separate the American bird from that of other 

 regions. The names of Gmelin and Latham are current for the species, but they are 

 based upon Sonnerat (as above), and upon the same basis appears the name " anosilice- 

 tns" (as given by Gray), which has priority. Sundevall, indeed, finds a still earlier de- 

 signation in nuKlosa, " Sparmm., Mus. Carls, t. 62." This I have not been able to look . 

 up, but as there seems to be some uncertainty about it, it may be best held in check. 

 Thus Gr.ay, in the Hand-list, gives "nuMlosa, Sparmm., M. C. t. 63," as a synonym of 

 No. 11082 (" infttscata, Licht.") ; while in 1863, in his List of British Birds, he has a 

 "nebulosa, Sparmm., M. C. t. 63," under Sterna eantiaca, t Gm. Without the work before 

 me, I can only presume that Sundevall's quotation of "t. 62" is pi. 62, and that Gray's 

 "nebulosa" is a slip for nuMlosa. 



In not adopting this name nuMlosa for the present species, I am influenced by the 

 following considerations : There appears to be another very closely-related species, or 

 rather variety, and it is uncertain to which one of the two nuMlosa belongs. This 

 species is given -by Gray, No. 11082, as "infuscata, Licht.," and put in a different sub- 

 genus. There are in the Smithsonian two specimens which I take to be this species : 

 one, No. 57093, from the Schlatter collection, marked " Sterna fuscata, $, ad., Insel 

 Candia;" and another, No. 28475, marked "Bengal," but without further labeling. 



* But the length of the tail, as in all Terns, varies very greatly, according to the age 

 of the elongated lateral feathers. A discrepancy of several inches is by no 'means 

 unusual in this subgenus and in Sterna. 



+ Latham quotes "nuMlosa, M. C. t. 63, pullus," as a synonym of his S. loysii var. y. 



