Bulletin of Zoological Nomenclature 221 PROPOSED USE OF THE PLENARY POWERS TO VALIDATE THE GENERIC NAME " HOPLITOPLACENTICERAS " (CLASS CEPHALOPODA, ORDER AMMONOIDEA) (UPPER CRETACEOUS) AS FROM PAULCKE, 1906, AND TO DETERMINE ITS TYPE SPECIES By C. W. WRIGHT (London) (Commission Reference : Z.N.(S.) 1197) The purpose of the present appUcation is to ask the International Commission on Zoological Nomenclature to give a direction as to the interpreta-tion of the nominal species Hoplites plasticus Paulcke, 1906, the type species of the genus Hoplitoplacenticeras Paulcke, 1906, and, having done so, to place the name of that genus on the Official List of Generic Names in Zoology. 2. In 1906 W. Paulcke described and figured a series of ammonites from the Upper Cretaceous Campanian stage in Patagonia. Among them was a group of forms which he regarded as transitional between the genera Hoplites Neumajrr, 1875, and Placenticeras Meek, 1876. He headed the section of his paper which dealt with this group (: 12 — 54) " Hoplites-Placenticeras " but later had a heading " Hoplito-Placenticeras ". He explains (: 17) that these " transi-tional " forms can be described as " Hoplitoplacenticeras " : those that show strong hoplitoid characteristics might, he suggested, be written with the " Hophto-" portion in roman, and the " -placenticeras " portion in itahc type, while the reverse method might be employed for those with placenticeratoid characteristics. Paulcke's ideas are so peculiar that I annexe below a facsimile of the passage in question : — Facsimile of the first complete paragraph on page 183 (= page 17 of separate) of Paulcke's paper Zwischenformen zwischen Hoplites und Placenticeras wiirden dementsprechend als Hoplitoplacenticeras bezeichnet. Wiegen Ho-plitenmerkmale vor, so ware der Name fiopZ^^oplacenticeras za schreiben, wiegen Placenticeratenmerkmale vor, so miisste Hoplito-placenticeras stehen. — Bei etwa Gleichwertigkeit der Merkmale wiirde kein Name hervorgehoben. — Als Beispiel eines echten Placenticeras ware Placenticeras placenta Meek anzufiihren, wahrend Placenticeras pacificum Smith nach obigen Auseinandersetzungen als )i.o^\\ioplacenticeras zu bezeichuen ware. • Dnter dem vorliegenden Material wiirden die Formen des plasticus-laevis als Hopliiop\a.centi-ceras bezeichnet werden konnen, wenn man es nicht vorzieht, sie einfacb noch Hoplites zu nennen. Bidl. zod. Nomend. Vol. 13, Part 7. June 1957.
Proposed use of the plenary powers to validate the generic name Hoplitoplacenticeras (Class Cephalopoda Order Ammonoidea) (Upper Cretaceous) as from Paulcke, 1906, and to determine its type species
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