PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 181 



called "Kjolikenmoddings" of Denmark, and iu the leavings of the 

 lake-dwellings of Switzerland the bones of Olor cygnus are found toler- 

 ably common, and likewise from the peat-bogs of England. From 

 Belgium, Prof. P. I. van Blueden has described a separate species as 

 Cygnus JierenthalsU* from "une phalange du pied." 



The subfamily Cygnimc is at the present time considered to embrace 

 nine recent .species, distributed in four different genera. 



This number is only one more than Ruppell already indicated in his 

 monograph, but amongst the eight considered by him are enumerated 

 Cairina moschata{Li^.) and Plectropterus riippelUi Sclat. {= gamhensis 

 Rtipp. uec Linn.). Blainville gave, in Compt. Esnd. VII, 1838, pp. 

 1022-1020, and Lesson, in Rev. Zool. 1839, pp. 321-324, an enumeration 

 of the species belonging to the genus, also comprising eight, having, 

 instead of the two last, adopted C. coscoroha (Mol.) and immutaMlis 

 Yarr., whilst, however, they did not distinguish between hewickii 

 Yaer. and columhianus (Ord). Eyton having published in 1838 his 

 "Monograph of the Anatidaj" separates these, and thus makes species. 

 SchleGtEL, in his synopsis of the genus (Mus. P.-B. 1866, VI, Anseres^ 

 pp. 78-83) enumerates eight 8i)ecies. He, it is true, adopts also coscoroha 

 (Mol.) as belonging to this genus; on the other hand, however, he does 

 not recognize G. immutaMlis Yarr, as a distinct species. 



LiNNyEUS only described one species of Swan under the name of Anas 

 cygnus, enumerating, however, the tame Swan among the synonyms as 

 var. mansuetus; but in 1779 Pallas had already separated the latter 

 specifically, and retained for it the title of cygnus, whilst the Hooper re- 

 ceived the name olor. 



Molina, in 1782, described the Chilian Swan as Anas melaneorypha. 



In 1788 Gmelin described nigricolUs after Bougainville and me- 

 lanocej)hala after Molina. In the mean time, as these two are synony- 

 mous with Molina's melaneorypha, the number of species known at that 

 time amounted still to only three. 



In 1790 Latham described atratus. In the same year it was described 

 by Bonnaterre under the name of Anser Kovoe-Hollandice. 



Lewis and Clarke, in their "Travels" (1814), separated the Ameri- 

 can Swan, which Ord, in the second American edition of Guthrie's 

 Geography iu the following year (1815), gave the systematic name Anas 

 colimibianus, thus making the fifth species. 



In 1830 Yarrell described Cygnus bewicMi as new, by which the 

 number of species was increased to six. In the same year Breiim in- 

 dicated C, islandicus as a supx)osed new species, which, however, is only 

 a synonym of Olor cygnus. 



The seventh species was added in the following year (1831) by Rich- 

 ardson, viz: C. buccinator from ISTorth America. 



The eighth dates from the year 1S38, when Yarrell introduced C. 

 immutaMlis into the system. 



* Jour, de Zool. I, 187:2, p. 288, (C. herrenthalsi Ibis, 1873, p. 434.) 



