22 



ALTRICIAL G-RALLATORES — HERODIONES. 



Genus HERODIAS, Boie. 



Hcrodias, Boie, Isis, 1822. Type, Ardca egrdta, Lixn. 



Gen. Char. "White Herons of large size, and without plumes, except in the breeding season, 

 when ornamented simply (in most species ^) by a long train of straiglit feathers, with thick shafts, 

 and long, sparse, decomposed, slender barbs, which grow from the dorsal region and overhang the 

 tail. Bill moderately slender, the upper and lower outlines almost parallel to near the end, where 

 gently curved, the culmen more abruptly so than the gonys, though the curve is quite gradual. 

 Mental apex reaching a point about midway between the tip of the bill and the eye ; malar apex 

 decidedly anterior to the frontal apex, and extending to beneath the posterior end of the nostrils. 

 Toes very long, the middle one about two thirds tlie tarsus, the hallux much less than one half the 

 former. Tibiaj bare for about one half their length, or for about the length of the middle toe. 



H, egretta. 



Anterior scutellaj of tarsus large, distinct, and nearly quadrate. Nuptial plumes confined to the 

 anterior part of the back, whence spring numerous long, straight, and thick shafts, reaching, when 

 fully developed, to considerably beyond the end of the tail ; each stem having along each side 

 very long, slender, and distant fibrilla'. Tail even, of twelve broad feathers. Lower nape well 

 feathered. Plumage entirely pure white at all stages and seasons. 



This genus, like Ardea, Garzetta, etc., is nearly cosmopolitan, being wanting only in the islands 

 of the South Pacific and in the colder latitudes of other regions. It comprises but a single Ameri- 

 can species, which has a more extensive range than any other of the American Herons, excepting 

 only Nyctiardea grisca na'via,^ its regular habitat extending from the United States to Chili and 

 Patagonia. In their immature stage and in winter plumage, the several Old World species closely 

 resemble the American species, as well as one another. But it is believed that in i'ull dress 

 the following distinctions will be found to hold good in the forms which we have been able to 

 compare. Gray's Hand-list (vol. III. pp. 27, 28) recognizes the following species : (1) //. idha, L., 

 of Europe, Africa, India, and Australia ; (2) II. egretta, Gmel., of America ; (3) H. intei-mcdia, V. 



1 An Old World species (H. plu^m'fcrus, Gould) has long jugular feathers with (lecoinposed webs. 



2 It is an unsettled ([uestiou, however, whether the Night Heron of Chili, Patagonia, etc., may not be 

 a distinct race (iV. grisea obscura ; see page 56). 



