18 BUREAU OF ANIMAL INDUSTRY. 



Which would leave, as type for the genus Tetrao, T. phaxirn>llnx, which was the 

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

 in 1858, who made it the type of a genus Pediocsetes. No species being now left to 

 bear the name Tetrao, it must be restored either to T. phoManettus (under the 

 unrestricted action of the principle of elimination), or to T. lyrurus (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 Linnsean 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 available 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 subgeneric sense to either or any of its com- 

 ponents. 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 can- 

 celed, and that the earliest name applied to any of the previously 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 afterwards to the rank of genera, then both names are to 

 be retained in a restricted sense for the new genera. 



THE CODE OF THE GERMAN ZOOLOGICAL SOCIETY, 1894. 



The Code (1894, 13-14) of the German Zoological Society contains 

 the following provisions regarding types: 



25. Sind fur eine Gattung verschiedene zultissige Namen annahernd gleichzeitig 

 aufgestellt worden, so dass die Prioritiit nicht festzustellen ist, so ist derjenige Name 

 '/.VL wahlen, fur welchen eine "typische Art" aufgefiihrt war. In alien dadurch 

 nicht zu erledigenden Fallen ist die Entscheidung des ersten Autors, welcher die 

 Synonymic der verschiedenen Namen nachweist, massgebend. 



26. Wird eine Gattung in mehrere neue Gattungen aufgelost, so verbleibt der alte 

 Gattungsname der als Typus anzusehenden Art. Ist eine solche nicht mit Sicherheit 

 festzustellen, so hat der die Auflosung vornehmende Autor eine der urspriinglich in 

 dieser Gattung enthalten gewesenen Arten als Typus zu bestimmen. Werden Unter- 

 gattungen zu Gattungen erhoben, so wird der Untergattungsname zum Gattungs- 

 namen. 



THE MERTON RULES, 1896. 



In the "Merton Rules" (Walsingham & Durrant, 1896. 14-1H) are 

 found the following passages relating to types of genera: 



40. The type of a genus must be one of the species originally placed in the genus 

 by its founder, but no species can be regarded as a possible type if it can be shown 

 that the founder of the genus had not seen it. 



[N. B. This and the follomng rule* (40-47) apply with equal force to the sections of 

 any grade.] 



