SPECIES 20 . ^NAS MARILA. 
SCAUP DUCK. 
[Plate LXIX.— Fig. 3.] 
Le petit Morillon ray^, Briss. vi, p. 416. 26. A.~Jlrct. Zool. JVo. 
498. — Lath. Syn. iii, p. 500. — Peale’s Museum, M. 2668. 
This Duck is better known among us by the name of the 
Rhie Bill. It is an excellent diver; and according to Willough- 
by feeds on a certain small kind of shell fish called scaup, 
whence it has derived its name. It is common both to our fresh 
water rivers and seashores in winter. Those that frequent the 
latter are generally much the fattest, on account of the greater 
abundance of food along the coast. It is sometimes abundant in 
the Delaware, particularly in those places where small snails, 
its favorite shell fish abound; feeding also, like most of its tribe, 
by moonlight. They generally leave us in April, though I 
have met with individuals of this species so late as the middle 
of May, among the salt marshes of New Jersey. Their flesh is 
not of the most delicate kind, yet some persons esteem it. 
That of the young birds is generally the tenderest and most 
palatable. 
The length of the Blue Bill is nineteen inches, extent twen- 
ty-nine inches: bill broad, generally of a light blue, sometimes 
of a dusky lead colour; irides reddish; head tumid, covered 
with plumage of a dark glossy green, extending half way down 
the neck; rest of the neck and breast black, spreading round to 
the back; back and scapulars white, thickly crossed with wav- 
ing lines of black; lesser coverts dusky, powdered with veins 
of whitish, primaries and tertials brownish black; secondaries 
white, tipt with black, forming the speculum; rump and tail co- 
verts black; tail short, rounded, and of a dusky brown; belly 
white, crossed near the vent with waving lines of ash ; vent black ; 
legs and feet dark slate. 
VOL. III. — z z 
