1. CYGNUS. 37 



Cygiuis sibilans, A^ilss. Skand. Faun., Fogl. 3rd ed. ii. p. 386 (1858). 

 Cj'gnus tuberculirostris, C. F. Dub. PL Col. Ois. Belg. iii. p. 300 



(1860). 

 Cygnus immutabilis, Teh, {vec Yarr.) Verh. z.-b. Ges. Wien, xii. 



p. 785 (1862) (Menzaleb, Egypt). 

 Cygnus unwiui, Hume, Ibis, 1871, p. 413 ; Salv. ibid, (note, =C. 



olor) ; Blanf. Str. Feath. vii. p. 100 (1877) ; Hume, ibid. p. 104 



( = olor juv.) (1878) ; Stejn. Pr. U.S. Nat. Mus. v. p. 195 (1882), 

 Cygnus, .«p., Stoliczka, J. A. S. B. 1872, p. 299 (Cutcb) ; Hume,Stv. 



'Feath. IV. p. 33 (1876), ^ii. p. 104 (1878). 

 Cygnus pelzelni, Stijn. Pr. U.S. Nat. Mus. v. p. 197 (Lake Men- 



zaleh) (1882) fjuu. ?). 



Yar. domestica. 



f Anas dircrea, Henn. Obs. Zool. p. 139 (1809). 



Cyg-nus immutabilis, Yarr. P. Z.S. 1838, p. 19 (Medway, England) ; 

 Bp. Camp. List, p. 55, n. 383 (1838) ; Fyton, Mon. Anat. p. 96 

 (1838) ; Blainv. Compt. Rend. vii. p. 1024 (1838) ( = ?C. olorferus) ; 

 Wiegm. Arch. f. Naturg. 1838, i. p. 371 ; Pelerin, Mag. N. H. 1839, 

 p. K2 (osteol. diff.); Less. Rev. Zool. 1839, p. 322; K.^B. Wirbelth. 

 Eur. p. Ixxxiv (note) (1840) ; Yarr. Br. B. iii. p. 121 (with fig.) 

 (1843); id.Gen.B. iii.p.510,n. 2(1844); Rchnb.Syn.Av.,^a.ta.toT:e3, 

 t. 106. f. 965 (1845) ; Bias, in Naum. Vog. Deutschl. xiii. 2, p. 227 

 (1860); Poivys, Ibis, 1860, p. 351 (Ionian Isl.) : Degl. ^ Gerbe, Orn. 

 Fur. ii. p. 47(3 (1867) ; Fgt. Sgn. Anat. p. 45 (1869) ; ? Flw. c^- Buekl. 

 Ibis, 1870, p. 338 (Epirus) ; Field, July 1871 ; G. R. Gr. Hand-list, 

 iii. p. 78, n. 10598 (1871) ; Brii.(/g. Zool. Glirt. 1875, p. 321 (=olor 

 var.) ; Sclat. P. Z. S. 1865, p. 466' (breeding) ; Southw. Tr. Norf. Nat. 

 Soc^W. pp. 258-260 (1876) ; Dress. B. Eur. vi. p. 429, pi. 419. fi". 1, 

 2 (heads) (1880) ; Sclat. P. Z. S. 1880, p. 506 ; Forbes, P. Z. S. 

 1882, p. 352 ; Ste)n. Pr. U.S. Nat. Mus. v. p. 192 (1882) ; B. O. 

 U. List Br. B. p. 120 (1883) ; Sau7id. Yarrell's Hist. Br. B. iv. 

 p. 340 (1884-85) ; Seebh. Hist. Br. B. iii. p. 478 (1885) ; Southic. in 

 Stevens. B. of Norfolk, iii. p. Ill (1890) ; Rchmu. J. f. 0. 1890, p. 80. 



Olor immutabilis, Bp. Cut. Met. Ucc. Eur. p. 68, n. 412 (1842). 



Cvgiuis olor immutabilis, Schleg. Rev. Crit. p. cxii (1844) (England, 

 "Holland). 



Cygnus olor a. immutabilis, Bp. Compt. Rend, xliii. p. 648 (1856). 



Cygnus olor, part., Schleq. Mus. P.-B., Anseres, p. 18, spec. 3 (Haar- 

 'lem) (1866) ; Gleb. fhes. Orn. i. p. 856 (1872); Sclat. List Vert. 

 An. 8th ed. p. 423, spec, e, q, r (1883). 



Polish Swau, Gum. P. Z. S. 1877, p. 379. 



Cygnus mausuetus, part.. Dub. Faun. Belg., Ois. ii. p. 416 (1892). 



Hybrids. 



Cygnus olor X Anser ferus, var. domesticus, Crommelin, Ibis, 1869, 



p. 127. 

 Cygnus olorc^' xC. ferus $ , Dunn, Naturalist, 1890, p. 281 ; Leverk. 



J.f. 0. 1890, p. 217. 

 Cygnus olor cj X Anser cinereus $ , Leverk. I. c. 

 Cygnus olor r^ X Anser domesticus J , Leverk. I. c. 

 Cygnus immutabilis X (Bernicla leucopsisx B. canadensis), Leverk. I. c. 

 Cygnus olor 2 X Anser cinereus i^, Leverk. I. c. p. p. 218. 

 Cygnus olor $ X C. atratus cJ , Leverk. I. c. 



