Genus— C T E N A N A S. 
Ctenanas Mathews, Austral Av. Rec., Vol. II., p. 90, 1914 . . Type L. eytoni, 
Leptotarsis Eyton, Monogr. Anatidae, pp. 29, 111, 1838, not 
Leptotarsus Guerin, 1831 . . . . . . . . . . Type L. eytoni. 
Also spelt — 
Leptotarsus Sehlegel, Mus. Pays-Bas, Vol. VI., Anseres, p. 87, 1866. 
Medium-sized Anatine birds with Anatine bill, long neck, long wings, long 
tail, very long legs and short toes. 
The bill is long, longer than the head, with the culmen ridge well defined, 
the sides of upper mandible somewhat depressed ; the small nostrils are 
placed high up on either side of culmen ridge near base of mandible. The 
edges of upper mandible bear obsolete serrations on their internal portion. 
The nail of the upper mandible is well defined and overhangs the 
under, but the tip is rounded, not pointed. 
The under mandible has a long spatulate tip ; the rami enclose an 
unfeathered triangular depression. 
The wing has the primary formula as in Dendrocygna. 
The tail is comparatively long with hard feathers ; it is about one-third 
the length of the wing and much longer than the metatarsus. 
The legs are long with long unfeathered tibia ; the metatarsus is reticulate 
throughout and is shorter than the tail, though noticeably longer than the 
middle toe without the claw. 
The toes are fully webbed ; the middle toe is less than the metatarsus 
but longer than the culmen. The hind toe is long and narrowly lobed. 
