CEYLON WATER BIRDS. 313 
specimens are wholly white, while others are almost entirely 
slate-gray. The remaining members of this group are either 
entirely white, or white on the wings, tail, and greater part of 
the body. 
Lastly, we have the Bitterns and Night Herons, six species, 
which are mainly nocturnal in their habits. These are stouter 
in build and not so long in the leg as other Herons, the measure- 
ment of the tarsus being less than that of the bill from gape 
to tip, except in one conspicuously short-billed species. All 
the Ceylon species are under 2 feet in length, in no case are the 
wings, back, and tail white, nor is there a change of plumage 
in the breeding season. 
Rough Key to Ceylon Ardetde. 
I.—Size large ; length 36 inches or over ; upper plumage 
gray. Genus Ardea. 
(a) Length about 38; middle of breast and abdomen 
black in adults, buff and gray in young. 
Ardea manillensis (Purple Heron). 
(b) Length about 39 ; middle of breast and abdomen 
white. 
A. cinerea (Gray Heron). 
(c) Length about 56; under surface of body chestnut 
in adults, streaked white and brown in young. 
A. goliath (Giant Heron). 
II.—Size medium ; 18 to 36 inches in length ; plumage all 
white, all gray, or with wings, tail, and greater part 
of body white. 
A.—Plumage wholly white, naked portion of tibia or hock 
much longer than inner toe and claw, tarsus longer 
than bill. Genus Herodias. 
(a) Length about 36; dorsal plumes in breeding 
season, but no crest or breast plumes; tarsus 
about 6, but variable. 
Herodias alba (Large Egret). 
