The polyclads (Platyhelminthes: Polycladida) from the Tropical Eastern Pacific: Commented checklist and description of a new species Author Ramos-Sánchez, Mariela E9D05B3F-CF64-48E3-B5ED-8D24E47F9D2A 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. rmariela220@gmail.com 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 13947260 40171C5B-90EB-4641-91FF-EA8CA2C60D23 Leptoplanella californica ( Woodworth, 1894 ) Stylochoplana californica Woodworth, 1894: 50 , figs 1–2 ( type locality: Gulf of California Mexico ( 26°48′0″ N , 110°45′22″ W ). Parviplana californica – Hyman 1953a: 314 (new combination and new record from California ). – Faubel 1984a: 165–167 (identification keys). Distribution La Paz Bay, Baja California Sur , and pelagic environment in the Gulf of California and off the coast of Sinaloa , Mexico . Habitat Pelagic obligate. Remarks Due to the presence of the species in the pelagic habitat, Woodworth (1984) and Faubel (1984a) determined Leptoplanella californica as a pelagic obligate species. Woodworth (1894) originally described the species as Stylochoplana californica , based on immature organisms, characterizing the external morphology of the body and scarcely the internal morphology of the species; Woodworth described a cuneiform body, the presence of nuchal tentacles, a short penis papilla and a bursa copulatrix (= Lang’s vesicle). Subsequently, Hyman (1953a) made a redescription of the species and reassigned it to the genus Parviplana as Parviplana californica , based on the length of the body, the arrangement of the eyes and the external morphology of the reproductive complex. Subsequently, Faubel (1984b) reassigned the species to the genus Leptoplanella , and made a complete redescription of the external and internal morphology of the male and female reproductive systems, in which he determined the presence of a penis papilla armed with a sclerotized and conspicuous stipe, as well as the seminal vesicle.