152 BulletinofZoologicalNomenclature50(2)June1993 OPINION 1717 Bucephalus Baer, 1827 and B.polymorphus Baer, 1827 (Trematoda): conserved in their accepted usage Ruling (1) Under the plenary powers all previous fixations of type specimens for the nominal species Bucephalus polymorphus Baer, 1827 are hereby set aside and microscopicpreparationno. 1655bintheZoologicalMuseum,HumboldtUniversity, Berlin(thelectotypeofGasterostomumfimbriatumSiebold, 1848)isdesignatedasthe neotype. (2) ThefollowingnamesareherebyplacedontheOfficialListofGenericNames inZoology: (a) BucephahisBaer, 1827(gender:masculine),typespeciesbymonotypyBuceph- aluspolymorphusBaer, 1827; (b) Rliipidocotyle Diesing, 1858 (gender: feminine), type species by subsequent designationbyNicoU(1914)GasterostomumminimumWagener, 1852(ajunior subjectivesynonymofMonostomagaleatumRudolphi, 1819). (3) ThefollowingnamesareherebyplacedontheOfficialListofSpecificNames inZoology: (a) polymorphusBaer, 1827,aspublishedinthebinomenBucephaluspolymorphus andasdefinedbytheneotypedesignatedin(1)above(specificnameofthetype speciesotBucephalusBaer, 1827); (b) galeatum Rudolphi, 1819,aspublishedinthebinomen Monostomagaleatum (seniorsubjective synonym ofthe specific name ofGasterostomum minitnum Wagener, 1852,thetypespeciesofRliipidocotyleDiesing, 1858); (c) campanulaDujardin, 1844,aspublishedinthebinomenDistomacampanula. (4) ThenameGasterostomumSiebold, 1848isherebyplacedontheOfficialIndex ofRejectedandInvalidGenericNamesinZoology(ajuniorobjectivesynonymof BucephalusBaer, 1827). (5) ThenamefimbriatumSiebold, 1848, aspublishedinthebinomen Gasterosto- mumfimbriatum and as defined by the lectotype designated by Baturo (1979), is hereby placed on the Official Index of Rejected and Invalid Specific Names in Zoology(ajuniorobjectivesynonymofthespecificnameoiBucephaluspolymorphus Baer, 1827). HistoryofCase2251 AnapplicationfortheconservationofthegenericandspecificnamesofBiuephalus polymorphus Baer, 1827 by thedesignation ofa neotypewas received from Dr B. Baturo{InlandFisheriesInstitute. Olsztyn. Poland)on27February 1978. Noticeof thecasewassenttoappropriatejournals.Thehistoryofthislong-standingcasewas summarised in notes on BZN 49: 6 and 62. After correspondence the case was republishedin BZN49: 6-11 (March 1992)withtheagreementofDrBaturo. Dr Srivastava (ZoologicalSurvey ofIndia. Calcutta), who opposed Dr Baturo's original applicationpublished in BZN 36: 30-36 (July 1979), wasnotified(August 1991) ofthe intention to republish it. Dr David I. Gibson (77(f Natural History BulletinofZoologicalNomenclature50(2)June1993 153 Museum, London, U.K.)hadalsowrittentoDrSrivastavainSeptember 1988.There hasbeennoreplytoeithercommunication. A shortened version ofDr Srivastava's comment (received January 1981) was published(BZN49:62-64)atthesametimeastherepublishedapplication,together with recent comments in support of Dr Baturo's application from Dr Gibson, DrO.N.Pugachev(ZoologicalInstitute,RussianAcademyofSciences,StPetersburg, Russia)andProfJ.C.Pearson(UniversityofQueensland,Australia).Acopyofthese commentswassenttoDrSrivastavaatthetimeofpubhcation. ItwasnotedonthevotingpaperthattheessentialdifferencebetweenDrBaturo's positionandthatofDrSrivastavawasthattheformerproposedconservationofthe established usage of the names Bucephalus and polymorphus, whereas the latter (following priority strictly) would transfer these names to the taxon known as Rhipidocotyle illensis (= campanula). Drs Gibson and Pugachev and ProfPearson opposedthereplacementoiRJiipidocotylebyBucephalus(andoiBucephalusauctt.by Gasterostomum)whichwouldresultfromadherencetopriority. DecisionoftheCommission On 1 December 1992themembersoftheCommissionwereinvitedtovoteonthe proposalspublishedinBZN49:9-10.Atthecloseofthevotingperiodon 1 March 1993 thevoteswere—asfollows: Affirmativevotes 25: Bayer, Bock, Bouchet(inpart). Cocks,Cogger, Corliss, Dupuis, Hahn, Halvorsen, Heppell, Holthuis, Kabata, Kraus, Macpherson, Mahnert, Minelli, Nielsen, Nye, Ride, Savage, Schuster, Starobogatov, Trjapitzin, Ueno,Willink — Negativevotes 4: Lehtinen,MartinsdeSouza,StysandThompson. Bouchet supported conservation of the usage of Bucephalus polymorphus but consideredthattheCommissionshouldnotbeinvolvedwithquestionsofsubjective synonymy such as the placing ofRliipidocotyle galeata and R. campanula on the Official List of Specific Names. (Editorial note. The type of Rliipidocotyle is the nominalspecies Gasterostomumminimum,asgiveninruling(2)(b). Ithaslongbeen thepracticetociteseniorsubjectivesynonymsoftypespeciesintheOfficialLists(in accordancewithRecommendation67BoftheCode)butinthisandallothercasesit is not to be inferred that the Commission takes any view on the taxonomic synonymy. R. campanula is placed on the List as a senior subjective synonym of R. illensis, repeatedly mentioned in this case; again the Commission has taken no viewonthesupposedsynonymyandtheplacingofnamesonOfficialListsconfersno specialstatusonthem(Article78foftheCode)). Lehtinen and Martins de Souza commented that with the current taxonomic knowledgeofthegroupitwaspreferablethatpriorityshouldapply.Styscommented: 'Incasesconcerningnamesofspecieswithcomplexdevelopmentitisbettertostay with the generally understood Principle ofPriority when discoveries in taxonomy lead to concomitant nomenclatural changes, rather than to make exceptions by invokingtheplenarypowers.Zoologistsstudyingsuchgroupsshouldexpectandbe preparedtoacceptsuchnamechanges". Originalreferences ThefollowingaretheoriginalreferencestothenamesplacedonOfficialListsandOfficial IndexesbytherulinggiveninthepresentOpinion: 154 BulletinofZoologicalNomenclature50(2)June1993 BucephalusBaer,1827,NovaActaPhysico-MedicaAcademiaeCaesareaeLeopoldino-Carolinae NaturaeCuriosorum, 13: 570. campanula, Distoma, Dujardin, 1844, Histoire naturelle deshelminthes ou vers intestinaux, p.435. fimbriatum, Gasterostomum,Siebold, 1848,Lehrbuchder vergleichendeAnatomiederwirbel- losen Thiere,vol. 1,p. 129. galeatum.Monosloma,Rudolphi, 1819,Enlozoorumsynopsis, cuiacceduntmantissaduplexel indiceslocuplelissimi,p.86. Gasterostomum Siebold, 1848, Lehrbuch der vergleichende Anatomieder wirbellosen Thiere, vol. 1,p. 129. polymorphus, Bucephalus, Baer, 1827, Nova Acta Physico-Medica Academiae Caesareae Leopoldino-CarolinaeNaturaeCuriosorum,13:570. Rhipidocotyle Diesing, 1858, Sitzungsberichte der Mathematisch-Naturwissenschaftlichen ClassederKaiserlichenAkademieder Wissenschaften,32:313. ThefollowingisthereferenceforthedesignationofGasterostomumminimumWagener,1852 asthetypespeciesofthenominalgenusRhipidocotyleDiesing, 1858: NicoU,W. 1914.JournaloftheMarineBiologicalAssociationoftheUK,(2)10:490. The following is the reference for the designation of the lectotype of Gasterostomum fimbriatumSiebold. 1848: Baturo,B. 1979.BZN36:33.