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 Euplanina horrida Sopott-Ehlers & Schmidt, 1975 Euplanina horrida Sopott-Ehlers & Schmidt, 1975: 204–207 , pl. 7 fig. a–c ( type locality: Santa Cruz Island, Galapagos Archipelago, Ecuador ). Euplanina horrida – Faubel 1983: 33–36 , fig. 3e (identification keys). — Westheide 1991: 44 (mentioned only). Distribution Santa Cruz Island, Galapagos Archipelago, Ecuador . Habitat Interstitial (coarse intertidal sediments) or rocks. Remarks Faubel (1983) considered E. horrida a very primitive species due to its of any penis papilla and seminal vesicle, its very simplified male tract, and a female system with Lang’s vesicle connected with the exterior by a Lang’s duct (ductus vaginalis). Between the two female apertures, an accessory female organ opens to the exterior independently.