NYCTICORAX. 169 
birds have ornamental feathers which looks as if they were fully adult, 
and therefore they may be birds of the second year, as it is quite evident 
that the grayer plumaged ones are very old and perfect in livery. 
“The white streak down the throat is often absent or reduced to a few 
spots. It appears to be absent equally in quite young birds and in old 
ones also, and it may be the result of inherent melanism in the species. 
“The white form is exactly similar in size to the gray form, and, when 
adult, has the same ornamental plumes. In the Pacific islands the two 
forms appear to interbreed, and produce white young ones mottled or 
streaked with slaty gray. I have been unable to recognize any of the 
many forms into which the reef heron has been subdivided by naturalists. 
Some birds are larger, as will be seen by the measurements of the tarsi 
given in detail below, and these larger birds have a slightly longer wing 
and a heavier bill, but no specific distinctions can be founded on these 
variations, which are very slight.” (Sharpe.) 
“The color of the soft parts is excessively variable. In the adult the 
bare portion of the tibia varies from dark grass-green to greenish plumbe- 
ous; the back and sides of the tarsus and the greater part of the toes are 
generally pea-green, sometimes duller, sometimes yellower; the front of 
the tarsus and the first joint of the mid toe black, but sometimes these 
parts are green, only patched or mottled with black, and sometimes the 
black extends along the ridges of all the toes; the color of the bill and 
bare skin in front of the eye varies from sienna-brown to chocolate ; some- 
times the bill is a sort of ight mahogany color, and the bare skin a 
sort of greenish brown; usually the bills are yellowish at the tips; the 
lower mandible is generally lighter, sometimes brownish horny, sometimes 
yellowish horny; and in the breeding-plumage the whole lower mandible 
becomes apparently a very decided, though dull, yellow; the irides vary 
from bright to deep yellow. I suspect, though we have not been able to 
- work it out, that these differences in color are due both to age and to 
season.” (/uime.) 
“Quite common along the reefs. The young were met with on various 
occasions far inland along fresh-water streams, but we never found fully 
mature birds in such localities.” (Bourns and Worcester MS.) 
So far as observed, this species is solitary and found only on rocky 
shores, usually where coral flats are exposed at low tide. 
Genus NYCTICORAX Forster, 1817. 
Bill stout; legs rather short; tarsus about equal to middle toe with 
claw and little longer than exposed culmen; tarsus covered with hexagonal 
scales; head decorated with two or three long, slender, nuchal plumes 
and a full crest. 
