328 NORTH AMERICAN BIRDS. 



diagnosis will show the relationship of the several forms usually recoguizi'd 

 as distinct species : — 



Species and Varieties. 



P. subis. Above lustrous blue-black ; beneath lustrous blue-black or brown- 

 ish-gray, uniform, or with the abdomen and crissum white, or whitish. Females 

 always with the throat and jugulum gray. 

 A. Adult males entirely steel-blue. 



a. Females and young males with the abdomen pure white. 



Feathers about the anus smoky-gray beneath the surface. 



Wing about 6.00; fork of tail, .80 deep. 9 and Juv. Abdominal and 

 crissal feathers always with dusky shafts, and with the concealed por- 

 tion grayish. Forehead and nape hoary grayish. ILib. Continental 

 North America, south into Northern Mexico .... \m: subis. 



Wing, 5.25; fork of tail considerably less. 9 ^"'' J"^'- unknown. 

 Hab. Galapagos ........ vav. concolor} 



Wing, 5.80 ; fork of tail, 1. 10 deep. 9 '"'J J"'^- unknown. Hub. 

 Chili ........... var./urcata.- 



Fealhers about the anus snowy-white beneath the surface. 



Wing, 5.50 ; fork of tail, .90 deep. 9 ''"d juv. Abdominal and cris- 

 sal feathers entirely snowy-white, — never with dusky shafts (except 

 g juv. in transition). Forehead dusky grayish-brown ; nape steel- 

 blue. Hab. Cuba and Florida Keys .... var. cryptoleuca. 



b. Females and young with the abdomen dusky grayish-brown. 



Wing, 5.50; fork of tail, .80. 9- Lower parts dusky grayish-brown, 

 the feathers bordered with lighter grayish, producing a squamate ap- 

 pearance. Juv. similar, but feathers of the upper part-s bordered with 

 whitish. Hab. Paraguay (V^ermejo River) . . var. el eg an s ." 



B« Adult males with the abdomen and crissuni pure white. 



a. Lower tail-coverts with the shafts pure white. ^ (adult) with the 

 throat, jugulum, and sides steel-blue. 



9 and jtiv. scarcely distinguishable from those of cryptoleuca. Hab. 

 Porto Rico and .lamaica (St. Domingo also ?) . . var. dontinicensis.* 



b. Lower tail-covert.s with their shafts dusky. <J (adult) with throat, jugu- 

 lum, and sides brownish-gray. 



Sides of the jugulum with a blue-black patch in the ^. Wing, 5.50; 

 fork of tail, .70 deep. Hab. Bolivia .... viii: domes t tea. ° 



^ Progne subis, var. concolor. Rirundo cmicnlor, Gotti.d, P. Z. S. 18.37, 22 (.lames I., Gala- 

 pagos). Progne c. Baikd, Kev. Am. B. 1865, 278. I'rogm modesla, GouLU, Birds Beagle, 39, 

 pi. v. (Same specimen.) 



^ Progne subis, var. furcata. Progne furcata, Baikd, Rev. Am. B. 1865, 278. (CliUe.) 



* Progne subis, var. eUgans. Progne clegans, Baikd, Rev. Am. B. 1865, 275. (Vermejo 

 River. .' Progne purpurea, Darwin, B. Beagle 38 (Montevideo, November), Bahia Blanca, 

 Buenos Ayres, September.) 



* Progne {subis var?) domiuicen.ii<i. ffirmulo dominiccnsis, Gm. S. N. T, 1788, 1025. Prague 

 d. March, P. A. N. S. 1863, 295 ; Baikd, Rev. Am. B. 1865, 279. 



* Progne (subis vox X) domesiica. Progne domestica (Vieill.) Baikd, Kev. Am. B. 1865, 282. 

 (Paraguay and Boli\-ia.) {Hirundo domestica, ViEii.i.. Nouv. Diet, xiv, 1817, 521.) 



