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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 internal 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 

 lamellae. Nostrils submedial, longitudinal, placed near the ridge, elliptical. 

 Head of moderate size, oblong, compressed; neck extremely 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 angular 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. (Esophagus very slender, at the lower part of the neck 

 a little dilated; stomach transversely elliptical, with the lateral muscles 

 extremely large, the epithelium 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. 



