The polyclads (Platyhelminthes: Polycladida) from the Tropical Eastern Pacific: Commented checklist and description of a new species Author Ramos-Sánchez, Mariela Doctorado en Ciencias Biológico Agropecuarias, Área Ciencias Biológico Agropecuaria y Pesquera, Ciudad de la cultura “ Amado Nervo ”, Tepic, Nayarit, 63000, Mexico. & Laboratorio de Sistemática de Invertebrados Marinos (LABSIM), Universidad del Mar, campus Puerto Ángel, Ciudad Universitaria, Puerto Ángel, Oaxaca, 70902, Mexico. text European Journal of Taxonomy 2024 2024-10-17 962 1 1 67 https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2683/12419 journal article 10.5852/ejt.2024.962.2683 2118-9773 40171C5B-90EB-4641-91FF-EA8CA2C60D23 Paraplanocera oceanica (Hyman, 1953) Aquaplana oceanica Hyman, 1953b: 191–193 , 204, 206, 208, figs 8–11 ( type locality: Tagus Cove, Isabela Island, Galapagos Archipelago, Ecuador ). Paraplanocera oceanica – Faubel 1983: 76 (new combination). Distribution Tagus Cove, Isabela Island, Galapagos Archipelago, Ecuador . Habitat Benthic (sandy bottom). Remarks Paraplanocera oceanica was described by Hyman (1953b) as Aquaplana oceanica . Hyman does not include it in the genus Paraplanocera due to the presence of an elongated cirrus papilla. However, Faubel (1983) proposed that the morphology of this structure could be due to the organisms having been fixed after a copulation process (because during copulation, the cirrus protrude through the male gonopore) and that this structure is a proper elongation of the cirrus sac (see Faubel 1983: 76 ); therefore, Faubel transferred the species to the genus Paraplanocera , citing additional characteristics such as the presence of a prominent Lang’s vesicle, a bursa copulatrix, absent seminal vesicle, and nuchal tentacles. Paraplanocera oceanica has a cirrus sac with an elongated penis papilla that is armed with small spines in the terminal region ( Hyman 1953b ).