ANATIDiE — THE SWANS — OLOR. 
423 
1. Cygnus (Linn.), 1758. 
b 2 . The yellow color at the base of the bill not extending to the nostrils. 
c. 1 Smaller: Total length about 1,150 mm; middle toe with claw about 125 mm; the 
yellow spot at the base of the bill making at least one third of the surface of the bill 
and lores. 
2. Bewickii (Yarr.), 1830. 
c 2 . Larger: Total length about 1,400 mm ; middle toe with claw about 140 mui; the 
yellow spot at the base of the bill making, at most, one fifteenth of the surface of the 
bill and lores. 
3. Columbianus (Ord.), 1815. 
a 2 . The distance from the anterior angle of the eye to the hind border of the nostrils equal to the 
distance from the latter to the tip of the bill. 
4. Buccinator (Rich.), 1831.” 
The North American species of Olor may be readily distinguished by the following characters : — 
1. O. columbianus. Tail-feathers usually 20 ; bill not longer than the head, the anterior end 
of the nostrils considerably anterior to the middle of the maxilla ; naked loral skin usually 
with a yellow oblong spot. 
2. O. buccinator. Tail-feathers usually 24 ; bill longer than the head, the anterior end of 
the nostrils reaching to about the middle of the maxilla ; naked loral skin entirely black. 
Size considerably larger. 
Through a misconception of statements made on p. 465 of the “ Fauna Boreali- Americana,” Yol. 
II., the author of a “Nomenclature of North American Birds” (Bull. U. S. Nat. Mus. No. 21) 
included Bewick’s Swan in the North American fauna. In this, however, it seems that he was 
in error, as pointed out on pp. 210 and 211 of Dr. Stejneger’s Monograph, before referred to. In 
view, however, of the possibility that this species may yet be found within our limits, we quote 
below, from Dr. Stejneger’s paper, its chief synonymy and principal characters : — 
“ Olor Bewickii, Yarr. (Bewick’s Swan).” 
“ Diagn. The distance from the anterior angle of the eye to the hind border of the nostrils is 
much longer than the distance from the latter to the tip of the bill ; the yellow color at the base 
of the bill does not extend to the nostrils, making at least one third of the surface of the bill and 
lores. Smaller : Total length about 1150 mm ; middle toe with claw about 125 mm.” 
Syn. — 1830. — Cygnus Bewickii, Yarrell, Trans. Linn. Soc. XVI. p. 453 (nee Rich. 1831 quae O. 
columbianus, Ord). 
1838. — Cygnus islandicus, Naum., Wiegm. Archiv IY. 1838, p. 364 (nec Brehm, 1830, quse 
Olor cygnus, Linn.). 
1838. — Cygnus Berwickii, Eyton, Monogr. Anat. PI. 18 (err. typ.). 
1840. — Cygnus minor, Keys. & Blas. Wirbelth. Europ. p. LXXXII. 
1842. — Cygnus melanorhinus, Naum. Yog. Deutschl. XL p. 497. 
1851. — Cygnus musicus, Kjierboll. Ora. Dan. PI. XLIV. (nec Bechst. quae O. cygnus, 
Linn.). 
1854. — Cygnus americanus, Hartl. Naumannia, 1864, p. 327 (nec Sharpl. quae columbianus, 
Ord). 
1856. — ‘ Cygnus Altumi, Homeyer,’ Bp. Cat. Parzud., p. 15. 
1866. — ‘ Cygnus Altumii, Badeker,’ Schlegel, Mus. P. B. VI. Anseres, p. 82. 
1880. — Cygnus Bewicki, Dresser, Birds of Eur. pt. lxxvii.-lxxix.” 
Olor cygnus. 
THE HOOPER SWAN. 
Anas cygnus, Linn. S. N. ed. 10, I. 1758, 122 ; ed. 12, I. 1766, 194. 
Olor cygnus, “ Bonap.” Ridgw. Proc. U. S. Nat. Mus. Yol. 3, 1880, 202, 222 ; Nom. N. Am. B. 
1881, no. 586. — Stejn. Proc. U. S. Nat. Mus. Yol. 5, 1882, 198. 
