532 PROCEEDINGS OF THE NATIONAL MUSEUM. tol. 42. 



than to Butorides virescens dorninicanus ^ of the intervening island of 

 Dominica. The wide geographical range of three of the continental 

 forms — Butorides virescens virescens, Butorides virescens antJionyi, and 

 Butorides virescens hypernotius'^, in striking contrast to the limited 

 distribution of most of the island races, is also worthy of note. 



The female of Butorides virescens appears to be, in color, absolutely 

 identical with the male; but is, in most cases, somewhat smaller, 

 though in some races, and even in certain regions within the range of 

 the same subspecies, is, if our series represents the truth, equally as 

 large as the male or even larger. Owing to this relative variation the 

 male is used as the basis for our comparisons. 



Birds in juvenal plumage differ considerably in color from adults, 

 being duller and more brownish on the upper surface of the body, 

 lacking the glaucous appearance, as well as the dorsal plumaceous 

 feathers, besides having more rusty edgings to the feathers, and 

 often ochraceous or buffy terminal spots on the scapulars; wing- 

 quills and greater coverts tipped, often broadly, with wliite or buffy; 

 other wing-coverts much more broadly margiried with whitish, buffy, 

 or ochraceous than m the adult ; median and 'some of the distal les- 

 ser coverts with subtriangular terminal shaft spots of buff; hind neck, 

 sides of neck, and sides of head much paler and duller, somewhat 

 streaked with dark brown or blackish (the sides of head particularly) ; 

 lower parts much paler — white, heavily streaked with dark earthy 

 brown, this color very little rufescent on foreneck, the streaks some- 

 times nearly or quite absent on the median line, especially of throat, 

 chin, and anal region; bill of a lighter color than in the adult, mostly 

 dull greenish, with only the culmen dusky, the mandible largely 

 Ught yellowish ; legs and feet dull greenish yellow or ohvaceous. From 

 this plumage the bhd passes gradually into the adult condition, 

 obtaining its full livery, under normal conditions, apparently by 

 ihe first breeding season. Birds not quite fully adult are paler 

 below than when in complete plumage; the neck is more reddish 

 or fulvescent, and paler; the upper surface of body has more 

 rusty edgings and a less glaucous bluish cast ; the wings have darker 

 and more rusty edgings. Immatures are apparently often smaller 

 than adults, though many in the above described juvenal plumage are 

 of full adult dimensions. 



Seasonal differences in color are usually slight, and consist mostly 

 in the slightly paler neck, and lighter, duller, more bluish upper parts 

 of worn summer specimens. Individual color variation, on the other 

 hand, is, in apparently all the forms of the species, considerable. It 

 consists chiefly in the depth of shade of the gray on the posterior 

 lower parts; the dark streaking on throat and breast, which in some 

 specimens is broad and distinct, in others almost absent, in some light 

 brown, in others black; the color of the posterior upper parts, which 



See p. 562. a See p. 549. 



