Revised nomenclature of the sea pen genus Balticina Gray, 1870 (= Halipteris Kölliker, 1870) (Anthozoa: Octocorallia) Author Pérez, Carlos Daniel 0000-0002-0866-1183 Grupo de Pesquisa em Antozoários - GPA, Centro Acadêmico de Vitória, Universidade Federal de Pernambuco, Vitória de Santo Antão, Pernambuco, Brazil. carlos.perez@ufpe.br Author Cordeiro, Ralf Tarciso Silva Grupo de Pesquisa em Antozoários - GPA, Departamento de Biologia, Universidade Federal Rural de Pernambuco, Recife, Pernambuco, Brazil. & Department of Zoology (Invertebrate Zoology), National Museum of Natural History, Smithsonian Institution, Washington, D. C., USA Author Williams, Gary C. Department of Invertebrate Zoology, California Academy of Sciences, San Francisco, California, USA Author Gomes, Paula Braga Grupo de Pesquisa em Antozoários - GPA, Departamento de Biologia, Universidade Federal Rural de Pernambuco, Recife, Pernambuco, Brazil. text Zootaxa 2021 2021-05-03 4966 2 237 244 journal article 6540 10.11646/zootaxa.4966.2.10 ed503ed0-e7ea-465e-90b9-83e2ff1d1b36 1175-5326 4736352 D96EDA1D-2651-45FC-A35A-957543199822 Kölliker’s Pavonaria and Halipteris Kölliker published the work Anatomisch-Systematische Beschreibung der Alcyonarien I. Die Pennatuliden , divided in three parts in two volumes (7 and 8) of the Abhandlungen, ausgegeben von der Senckenbergischen natuforschenden Gesellschaft . While Volume 8 was clearly published in 1872, there has been controversy over the publication date(s) of Volume 7. The Volume 7 has nine continuous manuscripts, without divisions, with 602 pages and 46 plates. The controversy is based on the presence of two Title Pages in Volume 7 (https://www.biodiversitylibrary.org/item/ 54845#page/9/mode/1up). The first Title Page bears Siebenten bandes drittes und viertes heft, mit XXVII Tafeln (Volume 7, parts 3 and 4, with 27 plates), with 1870 as publication date, and the Second Title Page bears Siebenter band , mit XLVI Tafeln (Volume 7, with 46 plates- including the previous 27 cited in the first Title Page) with the date 1869-1870. The presence of these two title pages hinders interpretation, since the book corresponds to the complete volume 7 (with all papers and plates), even though the first Title Page points only to parts 3 and 4. This suggests that individual papers may been written between 1969 and 1970, but there is no information about specific publication dates for each paper. In the same way, there are no Title Pages with single parts 1 or 2. So, there is no clear evidence of a previous and separate publication of parts 1 and 2. Kölliker’s paper is split into two parts—the fourth and ninth papers in the volume—with the latter being a continuation of the former [“Fortsetzung” (= continuation) on the Summary of the volume; “Schluss” (=end) on its own title page]. It is clear that the two parts were written in different moments, the first (pages 109-255) was written in August 1869 as indicated in the introduction (“Würzburg, in August 1869 ”). Even though these two parts were written in different moments, they seem to have been published together in only one Volume, the 7 (with all four Heft ). Some authors have treated these two parts of Kölliker’s work independently of each other, considering, arbitrarily, the first to have been published in 1869 and the second in 1870 (Deichmann, 1936; Williams, 1990 , 1995 ). Williams (1990 , 1995 ) considered that Kölliker had named Pavonaria and Halipteris in 1869 since both genera are listed in the first part of the work (pp. 123 and 124, respectively) with brief characterizations but without any associated species. This would be enough to establish availability, even though detailed descriptions of these taxa and the inclusion of species are found in the second part, Pavonaria on p. 578 and Halipteris on p. 583. However, as said before, there is no evidence that the first part of Kolliker’s work was published in 1869. In fact, a publication date of 1870 has been attributed to other genera created by Kölliker in the same work, such as Sarcophyllum and Godeffroyia , which had similar preliminary mentions in the first half (see Williams, 1995 ; WoRMS Editorial Board, 2021 ). We contacted libraries and tracked this publication and all citations of it, and there is no evidence of prior publication of parts 1 and 2 separately. Thus, we assume that Volume 7 has been published in full (parts 1 to 4) and considered the date printed in the title page of the whole Volume 7, 1969-1970, as publication date. Therefore, 1869- 1870 should be considered as the date of publication for both of Kölliker’s papers.