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Genus III.— CYGNUS, Meyer. SWAN. 
Bill longer than the head, higher than broad at the base, depressed, and a 
little widened toward the end, rounded ; upper mandible with the dorsal 
line sloping, the ridge very broad at the base, with a large, depression ; 
narrowed between the nostrils, convex toward the end, the sides nearly erect 
at the base gradually becoming more horizontal and convex toward the 
end, the sides soft and thin, with numerous transverse little elevated inter- 
nal lamellae, the unguis obovate ; nasal groove elliptical, sub-basal, covered 
by the soft membrane of the bill ; lower mandible flattened, with the angle 
very long, and rather narrow, the sides convex, the edges with numerous 
transverse lamellm. Nostrils submedial, longitudinal, placed near the 
ridge, elliptical. Head of moderate size, oblong, compressed ; neck ex- 
tremely long and slender ; body very large, compact, depressed. Feet 
short, stout, placed a little behind the centre of the body ; tibia bare for a 
very small space ; tarsus short, a little compressed, covered all round with 
angular scales ; hind toe extremely small, with a very narrow membrane ; 
third longest, fourth very little shorter; anterior toes covered with angu- 
lar scales for nearly half their length, then scutellate, and connected by 
broad reticulated entire membranes. Claws rather small, strong, arched, 
compressed, rather obtuse. Space between the bill and eye bare; plumage 
dense and soft. Wings long, broad ; primaries curved, stiff, the second 
longest. Tail very short, graduated, of twenty or more feathers. Oeso- 
phagus very slender, at the lower part of the neck a little dilated; stomach 
transversely elliptical, with the lateral muscles extremely large, the epi- 
thelium dense, with two concave grinding surfaces ; intestine long, and of 
moderate width ; coeca rather large, narrow ; cloaca globular. Trachea 
generally enters a cavity in the sternum, whence it is reflected, before it 
passes into the thorax ; no inferior laryngeal muscles. 
