BIRDS — CYGNINAE. 
757 
Sub-Family CYGNINAE. 
CYGNUS, Linnaeus. 
Cygnus, Linnaeus, Syst. Nat. 1735. Type Anas olor, Gmelin. (Gray.) 
Ch. — Neck very long. Bill longer than the head, (commissure longer than the tarsus,) the basal portion covered by a soft skin 
extending to the anterior half of the eye, the plane of the upper outline from eye to eye horizontal ; the lateral outline extending 
nearly straight to the commissure, or even sometimes widening slightly ; not half the width of the bill at tip. Nostrils situated 
;n the middle portion of the bill. Lower portion of tibia bare ; the tarsus much shorter than the foot, much compressed, covered 
with hexagonal scales, which become smaller on the sides and behind. Hind toe small, much elevated ; the lobe narrow. Tail 
of 20 or more feathers, rounded, or wedge-shaped. Sexes similarly colored. 
As North America possesses only one genus of Cygninae, I have combined the sub-family 
characters with the generic in the preceding diagnosis. By Wagler the peculiarities of the hill 
have heen made the basis of sub-divisions of the old Linnaean genus Cygnus, as follows : 
Cygnus. — Bill with a swollen fleshy tubercle at the base of culmen. Teeth of the edge of 
bill projecting and visible from the side. 
Olor, Wagler. — No tubercle at the base of bill. Teeth of the edges of bill not projecting. 
Other members of Cygninae are Chenopis, embracing the Australian black swan, and 
Coscoroba, a South American white species with feathered lores. The black-necked swan of 
South America belongs to the sub-genus Cygnus. 
There are certain peculiarities of trachea and sternum which distinguish the genus and it s 
species in a marked degree. 
The two North American species of swan belong to Olor as restricted, with the following 
diagnoses : 
Tail feathers 20. Bill as long as the head. The anterior end of nostrils considerably beyond 
the middle of commissure. Black naked skin at base of bill, with a reddish spot anterior to the 
eye C. americanus. 
Tail feathers 24. Bill longer than head. Anterior end of nostril opposite the middle of 
commissure. Skin at base of bill entirely black... 0. buccinator. 
Comparative measurements of species. 
Catal. 
No. 
Species. 
Locality. 
Sex. 
Length. 
Stretch 
it' wings. 
Wing. 
Tail. 
Tarsus. 
Middle 
its claw 
alone. 
Bill 
above. 
Along 
gape. 
Specimen 
measured. 
1197 
do. 
9919 
9978 
Washington, D. C . . 
9 
21.50 
21.75 
22.00 
21.20 
22.00 
24.70 
7.20 
4.06 
5.40 
0.74 
4.20 
3.72 
55.50 
54.00 
81.00 
Fresh .... 
Near 32° L.. ....... 
8.68 
8.50 
'■8.50 
9.62 
8.10 
8.20 
4.12 
4.32 
4.92 
4.54 
4.64 
5 90 
" 5.42 
5.58 
6.44 
6.00 
6.46 
0.90 
0.86 
0.74 
0.84 
4.20 
3.82 
4.02 
4.50 
4.34 
4.58 
3.86 
3.64 
3.60 
4.22 
4.10 
9980 
9775 
9977 
5470 
do. 
3 
21.00 
21.00 
58.50 
78.00 
Fresh .... 
