46 
BULLETIN OF THE NUTT ALL 
DESCRIPTION OF A NEW DUCK FROM WASHINGTON 
ISLAND. 
BY THOMAS H. STREETS, M. D., PASSED ASSISTANT SURGEON, U. S. N. ’ 
Cliaulelasmua couesi. 
Bill nearly as long as the head, ahont as deep as broad at the base, 
depressed anteriorly, sides nearly parallel but converging slightly toward 
the base, tip rounded, and unguis abruptly curved ; frontal angle short 
and obtuse ; dorsal line at first sloping, rather more so than in G. strepe- 
rus, anterior portion broad, straight, and flattened. Internal lamellae 
numerous, small, and closely packed, about seventy-five in number, — in 
streperus only about fifty. Nostrils sub-basal, lateral, large, and oblong. 
Plumage {immature). Head above dark brown, the feathers tipped 
with a lighter shade ; frontal feathers with the central portion black, and 
edged with brownish -WThite ; throat and sides of head brownish-white, 
shafts of the feathers brown, a small brown spot at the extremity of each ; 
lower portion of the neck and breast all around with the feathers marked 
with concentric bars of black and light reddish-brown ; under surface 
of the body white, each feather with a broad dark band near the extrem- 
ity, which gives to this region a mottled aspect ; toward the tail the 
white of the abdomen assumes a dull reddish-brown tinge ; the brownish- 
red color becomes more decided on the flanks and sides of the body where 
covered by the wings. On the back the plumage is more mature. Color 
dark brown marked transversely by fine wavy lines of black and white ; 
scapulars dark brown and fringed with a narrow rim of reddish- 
brown. Middle wing-coverts chestnut ; greater, velvet black ; speculum 
pure white, the inner web of the w’hite feathers grayish-brown ; in the 
third feather in the speculum, counting from within, the white gives 
place to a hoary gray with a black outer margin ; the primaries light 
brown, the portion of both webs nearest the shaft lighter ; shaft light 
brown. Tail containing fourteen feathers, hoary plumbeous-gray, under 
surface lighter and shining ; under tail-coverts crossed by transverse bars 
of black and white ; upper coverts composed of dark brown and black 
feathers mingled. Under wing-coverts and axillars pure white. Bill 
and feet black, somewhat lighter on the inner side of the tarsus. Tibia 
bare for about half an inch. Length, 17 inches ; wing, 8 ; tarsus, 1.40 ; 
commissure, 1.65 ; culmen, 1.45 ; height and breadth of bill at base, .55 ; 
average width of bill, .55. First toe, .30 ; second, 1.48, including claw, 
shorter than third toe without claw ; third toe, 1.88 without claw, longer 
than outer toe without claw ; outer toe, 1.75. 
