ARDEIDJ3 — THE HERONS — ARDETTA. 
73 
tips of primary-coverts, secondaries, and inner primaries, rich cinnamon-rufous ; large area, cov- 
ering middle wing-covert region, pale ochraceous, or huff ; remiges and primary-coverts blackish 
slate, except at tips. “ Bill dark olive-brown above, edges of upper mandible and bare frontal 
space yellow ; lower mandible pale yellow, inclining to flesh-color ; iris yellow ; feet dull greenish 
yellow ; claws brown” (Audubon). Adult female : Similar to the adult male, but the greenish 
black replaced by brown (varying from umber-drab to cinnamon, the pileum darker and usually 
opaque blackish dusky) ; the buff stripe along outer border of scapulars much broader and more 
conspicuous, and the stripes on the foreneck (usually but not always) more distinct. Otherwise 
exactly like the male. Youn<j : Similar to the adult female, but the feathers of the back and 
scapular region tipped with buff ; the striped on the foreneck also (usually) more distinct. 
Length, about 12.00-13.50 ; expanse, 17.00-18.00. Weight, about 4-f- ounces (Audubon). 
Wing, 4.30-5.25 ; tail, 1.60-2.10 ; culmen, 1.60-1.90 ; depth of bill, .28-35 ; tarsus, 1.50-1.75 ; 
middle toe, 1.40-1.60 ; bare portion of tibia, .45-.50. 1 
With a considerable series of specimens before us, we can observe no geographical variations 
other than the slightly smaller size of skins from Demerara and Tehuantepec. As to colors, no 
tropical examples are brighter than two males from the eastern United States (1549, Carlisle, Pa., 
and 1090, District of Columbia). The range of individual variation in color is also very slight, 
though very great as to dimensions. 
In a considerable series of Least Bitterns from Guatemala, kindly submitted to us for exam- 
ination by Mr. Osbert Salvin, there is a single specimen, which, while agreeing very closely in 
plumage with the adult male of the common North American species, is so different in propor- 
tions as to leave little doubt of its specific distinctness. The tarsi and toes are disproportionately 
shorter than in A. exilis, the former measuring only 1.15 and the middle toe 1.12, while the inner 
toe is just perceptibly longer than the outer, measuring 0.98 against 0.95. The tibiae are com- 
pletely feathered, even more so than in A. involucris. The other specimens, chiefly from the Lake 
of Duenas, are all typical A. exilis , mostly young of the year, evidently reared in the locality. 
Without venturing to name this bird, we give below a full description. 2 
1 Extremes of twenty-one adult examples. 
2 Chak. Similar to A. exilis, but with the tarsi and toes disproportionately shorter, and the tibiee 
completely feathered. Adult $ : Pileum uniform black, with a faint greenish gloss ; remainder of the 
head ochraceous, growing gradually more rufous on the superciliary region ; nape bright rufous, becoming 
nearly chestnut on the lower portion ; sides of the neck like the cheeks. Chin and throat immaculate 
pure white, the lower part of the latter with a very faint wash of pale buff medially ; foreneck creamy 
white, with a narrow mesial stripe of grayish brown. Sides of the breast brownish black, the 
feathers tipped with light fulvous ; remaining lower parts white, tinged with light creamy buff, most 
distinct laterally ; tibia; deep fulvous ; lining of the wings grayish white, purer white anteriorly, where 
is a spot of mixed ochraceous and dusky on the carpal joint ; axillars ash-gray ; under-surface of the 
remiges similar, but deeper. Back and scapulars glossy black, with a faint green reflection, the outer 
row of interscapular feathers edged exteriorly with light buff, forming, when the feathers are disarranged, 
a somewhat Y-shaped mark, defining the lateral and posterior boundaries of the interscapular region. 
VOL. i. — 10 
Adult male. 
