328 NORTH AMERICAN BIRDS. 



diagnosis will show the relationship of the several forms usually recognized 

 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. 



u. 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 ^^^ <^"^- Abdominal and 

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

 tion grayish. Forehead and nape hoary graj'ish. Hab. Continental 

 North America, south into Northern Mexico .... var. sttbis. 



Wing, 5.25 ; fork of tail considerably less. 9 ^"'1 -^"^'^ unknown. 

 Hab. Galapagos var. con color } 



Wing, 5.80; fork ol' tail, 1.10 deep. 9 and Juv. unknown. Hah. 

 Chili ........... \av.furcata.'' 



Feathers about the anus snowy-ivhite beneath the surface. 



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

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

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

 blue. Hab. Cuba and Florida Keys .... vav. cr y p to! e uca . 

 b. Females and young with the abdomen dusky grayish-bi-own. 



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 parts bordered with 

 whitish. Hab. Paraguay (Vermejo River) . - . var. elegans.^ 



B. Adult males with the alidomen and crissum pure white. 



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

 throat, jugulum, and sides steel-blue. 



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

 Porto Rico and Jamaica (St. Domingo also ?) . . var. dominicensis.^ 



b. Lower tail-coverts with their shafts dusky. $ (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. Bohvia .... \ar. domesti cu .^ 



1 Proijne subis, var. concnlor. Hirundo concolor, Gould, P. Z. S. 1837, 22 (James I., Gala- 

 pagcs). Progne c. Baird, Rev. Am. B. 186.5, 278. Prognc modesta, Gould, Birds Beagle, 39, 

 pi. V. (Same specimen.) 



2 Progne sicbis, var. furcata. Prognc f areata, Baird, Rev. Am. B. 1865, 278. (Chile.) 



^ Progne subis, var. elegans. Progne clegans, Baird, Rev. Am. B. 1865, 275. (Vermejo 

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

 Buenos Ayres, September.) 



* Progne (subis var?) dominicensis. Hirundo dominicensis, Gm. S. N. T, 1788, 1025. Progne 

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



5 Progne (subis var 1) domestica. Progiu domestica (Vieill.) Baird, Rev. Am. B. 1865, 2S2. 

 (Paraguay and Bolivia.) (Hirundo donustica, Vieill. Nouv. Diet, xiv, 1817, 521.) 



