564 TRANSACTIONS OF THK WAGNER FREK 



erature of mollusks, chiefly auctioneers' and amateurs' catalogues, are removed 

 from the path of the worker. 



As to the requirements for publication, it is now admitted with practical 

 unanimity that the actual date of publication in print is the only date to be con- 

 sidered in discussing the priority of a published name; and, where this date is 

 uncertain, no name of certain date and possible priority should be rejected, if 

 in use, until a certainty is established for the competitor. 



Some authors, probably little realizing the mischief they were doing, 

 have rejected names because they differed only in gender, from other prior 

 names. This is in opposition to the general usage of naturalists, to the funda- 

 mental object of nomenclature, and does not appear to have any warrant in 

 usefulness to science, or in any other direction. Such proceedings cannot be 

 accepted. Two names are either identical or not. If identical, one is a syn- 

 onym ; if not identical, it can stand ; other things being equal. 



The moment one allows uncertainty of application to enter into the office 

 of a rule, there follows mischief more or less extensive. It must be tested by 

 the question (i) is it necessary? and (2) if not unavoidable does it make for 

 fixity of nomenclature? If the second question is answered in the negative, 

 the change is condemned ipse facto. 



The determination of priority is often a very complex matter. The writer 

 has come to the conclusion that : 



V. If once a synonym, a generic name must be regarded as always a 



synonym. 



Formerly, on various grounds, the writer hesitated to take this position, 

 but has been gradually forced to believe that safety lies that way alone. 



VI. The first species in a list, where no type is mentioned under a new genus, 

 is not necessarily to be taken as the type. The type of the first reviser of 

 the genus should stand unless there are weighty reasons to the contrary. 

 In Linnean groups, unless the type has been otherwise fixed, his rule 

 should be followed to take the most common, best known or officinal 

 species, but if another has been deliberately selected by a reviser, the 

 latter must stand. In present-day work there can be no excuse for the 

 non-specification of a type by the author of a genus. 



VII. The author having proposed a genus has no further authority over it. He 

 may not alter the name, change the selected type, or do anything which he 

 might not be authorized to do to a genus proposed by some one else. 



VIII. In selecting a type, a species not mentioned by the author of the genus 

 in the original list of species given when the genus was proposed, can- 

 not be chosen. 



IX. If a genus is divided and portions of it erected into new genera, a portion 

 must be left to bear the original name. 



