44 CODE OF NOMENCLATURE. 



6. cupido (Tympanuchus Glog., 1842; Cupidonia Reich., 1850) : 



7. bonasia (Bonasia Steph., 1819, -)- Bon., 1828) ; 



which would leave, as type for the genus Tetrao, T. phasianclius, which was 

 the last species to be removed from the genus Tetrao, its removal being 

 made by Haird in 1858, who made it the type of a genus Pediocates. No 

 species being now left to bear the name Tetrao, it must be restored either to 

 T. phasianclius (under the unrestricted action of the principle of elimina- 

 tion), or to T. lyntnis (under the above-proposed restricted action of the 

 principle of elimination). In the latter case, this ancient Greek name for 

 a European species of Grouse would be still retained in nearly its original 

 sense. 



As in the case of Tetrao, so in the cases of many Linnasan and Brissonian 

 genera, it has happened that, in the process of gradual elimination, exotic (or 

 non-European) species only have been finally left in the original genus, 

 while the European species have successively been made types of separate 



genera. 



CANON XXIV. When no type is specified, the only avail- 

 able method of fixing- the original name to some part of the 

 genus to which it was originally applied is by the process of 

 elimination, subject to the single modification provided for by 

 Canon XXIII. 



CANON XXV. A genus formed by the combination of two 

 or more genera takes the name first given in a generic or sub- 

 generic sense to either or any of its components. If both or all 

 are of the same date, that one selected by the reviser is to be 

 retained. 



REMARKS. The propriety of this rule is too obvious to require special 

 comment. It therefore follows that a later name equivalent to several earlier 

 ones must be cancelled, and that the earliest name applied to any of the pre- 

 viously established genera thus combined is to be taken as the designation 

 of the new combination. 



CANON XXVI. When the same genus has been defined and 

 named by two authors, both giving it the same limits, the later 

 name becomes a synonym of the earlier one ; but in case these 

 authors have specified types from different sections of the genus, 

 and these sections be raised afterward to the rank of genera, 

 then both names are to be retained in a restricted sense for the 

 new genera. 



