2 20 Elliot, Some Genera and Species. Llulv 



ON SOME GENERA AND SPECIES. 



BY D. G. ELLIOT, F. R. S. E. 



In my little book on the ' Wild Fowl,' I gave some reasons 

 why, in my opinion, the genus Olor of Wagler, Isis, 1832, 

 p. 1234, should not be employed in preference to Cygnus 

 Eechstein, Orn. Taschenb., Vol. II, p. 404 (1803). In order 

 to bring this question to the attention of the Committee of 

 Nomenclature, some of whose members probably have not read 

 what I have written, I propose to consider Olor as diagnosed 

 by Wagler, and afterwards by Stejneger (Proc. U. S. Nat. Mus., 

 1882, p. 174), and show what seems to me, the entire insufficiency 

 of the generic values of the characters advanced by these 

 writers, and also that they are by no means in accord as to which 

 of these should be selected to represent the genus. 



Wagler divided the Swans into three genera, Cygnus, Olor and 

 Chenopis. With the last, containing the Black Swan, I have at 

 present nothing to do. Cygnus is diagnosed as follows : " Aeus- 

 sere Merkmale dieser Sippe bestechen in dem Hocker von der 

 Stirn und in dem Daseyn der Nagelkuppe am Oberkiefer." In 

 this genus he placed the Mute Swan, Cygnus gibbus Bechst. = C. 

 olor Gmel. By the above it will be seen that the characters 

 relied upon as generic are the knob at the base of the bill, and 

 the nail on the tip. Olor contains the rest of the White Swans, 

 omitting only cohwibianus Ord. The diagnosis for this is as fol- 

 lows ; "Der Oberkiefer , ohne Nagelhuppe ; die Stirn ohne 

 Hocker : " Thus the presence or absence of the knob and nail on 

 the bill are the only characters. In some remarks after the 

 species he makes certain comparisons of the anatomy, such as 

 the windpipe, muscles of the crop (Magen), etc., but the charac- 

 ters for the genera are as quoted above. 



Stejneger (1. c.) has quite another diagnosis, and not only 

 rejects all the characters relied upon by Wagler, but actually em- 

 ploys as a specific character the chief one, the knob (Hocker) 

 given by Wagler to distinguish his two genera. 



For facility of comparison I here give Stejneger's definition of 



