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NOTES ON THE GENEEA CYFRJEA AND TRIVIA. 

 By H. 0. N. Shaw, F.Z.S. 

 Read 12th March, 1909. 

 PLATES XII AND XIII. 



Aftee systematically workiDg at the genera Cyprcea and Trivia, aud 

 paying particular attention to synonymy, dates of publication of the 

 species, references and figures cited in the original descriptions, etc., 

 I have been induced to publish the results obtained with regard to 

 certain species with the hope tliat they may be of use to workers on 

 these genera. 



In the first place, I noticed that several species in both genera stand 

 at the present time with specific names which have been employed 

 previously to their present use by various authors to designate what 

 they believed at the time to be new species, but which have proved to 

 be synonyms or only varieties of earlier species. Gmelin is the chief 

 offender in this respect, as he described a considerable number of species 

 from figures of early writers, giving very brief and inadequate 

 descriptions, and often describing the same shell in different states of 

 growth. 



I had always understood that if a specific name had been used 

 once, even though in error, and therefore became a synonym, it could 

 never be employed again, or, to use a well-known expression, " Once 

 a synonym, always a synonym." ^ On inquiry from various eminent 

 conchologists and nomenclaturists, I find they are all of the same 

 opinion, and state that species bearing a name that has been used before 

 in the same genus must be renamed. Those species which require 

 renaming, witli the names I propose for them, will be found in this paper. 



The following is the general idea of the rules now usually recognized 

 on which I have made the changes : — 



1. A specific name used once, even though a nonien nudum or 

 synonym, cannot be used again in the same genus. 



2. A name given to a species, believed by the author to be new, 

 and which has proved to be only a variety of a prior species, can 

 retain the original name (being reduced to varietal rank), even though 

 the same name had been used previously either for a good species or 

 for what now is a synonym in the same genus. 



3. Two or more species in the same genus can have the same 

 varietal name ; e.g., minor, major, alba, piriformis, oblonga, etc. 



4. A name used to designate a fossil shell, even though now 

 a synonj^m, cannot be used for a recent shell of the same genus, and 

 vice versa ; but a name used to designate a fossil can also be used 

 as a varietal name of a recent form, or the reverse, and any number 

 of varietal names may be standing at the same time in the same fossil 

 and recent genus. 



Before attemj)ting these notes, besides the various monographs aud 

 works referred to, I have carefully studied Senor Hidalgo's excellent 



1 Dall, Trans. Wagner Free Inst., 1895, vol. iii, pt. iii, pp. 561-5. 



