HYDROCHELIDON NIGKA, WHITE- WINGED TERN. 709 



DiAG. H. nigrttf pallio scMstaceo-nigro, caudd crissoque albis, auUhvacMis albieantihus, alts 

 l)litmbeis, remiyihus argentato-fuscis rhachidihus albis, rostro rubescente-niyro, ptdibus 

 rubris. 



Hab. — Europe, «fec. Accidental iu North America (one instance known). 



Adult, summer pJumafje. — (No. 66213, Mus. Smitbs. Inst. 9, Lake Koskonong, Wiscon- 

 sin, July 5, 1873, T. Kumlein.) Bill black, -with a reddish tinge ; feet red ; chivrs black. 

 Head and neck all around and whole under parts to the crissum pure black, shading 

 on the back and scapulars into dark slatj-plumbeous. Wings dark silverj-})lundjeous, 

 fading into white along the fore-arm border; the quills silvered dusky, with white 

 shafts and a dull white area on the greater part of the iuuer webs of the primaries. 

 Lining of wings sooty-blnckish, varied with dull white along the border. Tail, with 

 its coverts, both above and below, white, abruptly contrasting with the black of the 

 belly and the dark slate of the rump. The tail feathers shaded with pearlj--gray to- 

 ward the ends. 



Length (of skin), 8 ; wing, 7.50 ; tail, 2.75; the emargination under 0.50; bill along 

 culmen. 0.90; along gape, 1.20; height at base, 1.20; tarsus, 0.75; middle toe and 

 claw, 0.87. 



The series of specimens before mc does not fully illustrate the changes of idumage 

 of thi.s* species. It shows, however, that the various plumages are closely coincident 

 with those of U. lar>formis, already detailed. Immature birds, plumbeous above and 

 mostly white beneath, may be recognized from the sanie stage of H. lariformis by the 

 hoary-white fore-arm border of the wing, and contrast of white upper tail-coverts with 

 the plumbeous of the back. 



As stated in the Check-list, p. 137, a specimen of White-winged Tern 

 ■was taken in Wisconsin, July 5, 1873, by Mr. Thure Kuinlein, and pre- 

 sented to the Smithsonian by Dr. T. M. Brewer. The individual is a 

 female, iu i^erfect breeding dress, and was said to have contained well- 

 formed eggs in the ovary, leading to the belief that it would have 

 bred iu the vicinity before long. This, so far as I know, is the first and 

 ouly instance of the occurrence of the species iu this country. I have 

 carefully compared the specimen with European ones, tindiug it identi- 

 cal in every particular. 



Section Megai^optere^e. 



I have already presented tlio character of Ihe "Noddy" group of Terns, as drawn 

 from the leading genus, Anous. Beside this principal form, with its several species, 

 there are two others, namely, Ncvnia'^ and Frocclstcriiai. The last named is cinereous, 

 and very near Auous ; the former is unique, in possession of long, white, curly plumes 

 on each side of the head. Gjifiist is a peculiar intermediate genus, pure white, with a 

 singularly .shaped bill. J«o«« alone occurs in this country. 



Gcmis ANOUS, Leach. 



<C SUrna, LiNN., Syst. Nat. i, 1758, uvc 1735. 



< (invia, Binss., Orn. vi, 1760, 199, mv MiiiiK.— Sw., Classif. B. ii, 1837, 373 {stolida). 



" XodiiiuH, Kak., 1815 ?" ( Grmj). 



= Noddi, Cuv., R. A. i, 1817, 521 (stoUda). 



=iAnouH, Lkacii, Steph. Gen. Zool. xiii, 1826, 139 {stolida). 



^ M( (/alopttrns, Bou:. Isis, lb26, 980 (stolida). 



= Utolida, Lkss., Tr. Orn. 1831, 620 (stolida). 



= At/aiKiphroii, (ii.oGKii, 1842. (Gray.) 



Gk.v. Cuai;. Bill much longer than the tarsus, rather exceeding the middle foe and 

 claw, about eiiualing the head, moderately robust, depres.sed, and as broatl as high at 



•N.4:nia, lioie, Isis, 18^4), 189 {= Larosterna, Bi.yth, Cat. Asiat. Soc. 1849, 2y3=/Hca, 

 Jai!I)., t'ontr. Orn. 18.'-,0. 3»). 



N.KMA i.NCA. — Sterna iina, Lkss., Voy. Ccxiuille, 1826, 731, pi. 47 ; Auous hica, Gkay, 

 Gen. of B. iii, 1^49, 6(il ; Larosterna inva, Blvth, /. c. ; Inva mystucaU«, Jahi>., /. c 



Ildl). — South America (I'eru and Chili). 



t I'i:()(Ki.sTi;i:.VA, Lafr., Rev. Zool. l^Jl, '242. The several nominal species of this 

 section may ))e reduced to two at most; I hav»^ recognized but one. South Seas and 

 Australia. 



t Gygis, Wagl., 1832; type alba. The single species inhabits the South Seas. 



