First records and two new species of sipunculans (Sipuncula) from the Southern Mexican Pacific Author Silva-Morales, Itzahí ADA5A4BD-EB4E-47E3-A6A7-D3E1FDA64ED3 División de Posgrado, El Colegio de la Frontera Sur, Unidad Chetumal, Quintana Roo, Mexico. itzahi_marley.gwn@hotmail.com Author Gómez-Vásquez, Julio D. BD3A3DE1-21F5-4B54-A707-361BE8E90DB9 Laboratorio de Sistemática de Invertebrados Marinos (LABSIM), Universidad del Mar campus Puerto Ángel, Ciudad Universitaria, Puerto Ángel, Pochutla, Oaxaca 70902, Mexico. gomezvjuliod@gmail.com text European Journal of Taxonomy 2021 2021-03-25 740 1 77 117 http://dx.doi.org/10.5852/ejt.2021.740.1283 journal article 7588 10.5852/ejt.2021.740.1283 504278d0-5689-4adb-9350-3e97392bfbf0 2118-9773 4643194 07F1B593-9F4F-4B32-88D9-ADC5CA0BEB84 Family Phascolosomatidae 1. Introvert much longer than twice the trunk length; hooks, if present, with basal spinelets; nephridia usually bilobed ....................................................................................... Apionsoma ........2 – Introvert less than twice trunk length; hooks without basal spinelets; nephridia unilobed ............. ........................................................................................................................... Phascolosoma ........4 2. Body wall muscles divided into separate bands ................................................................................. ................................................................... Apionsoma ( Edmonsius ) pectinatum ( Keferstein, 1867 ) – Body wall with continuous muscle layers ........................................ Apionsoma ( Apionsoma ) ........3 3. Papillae, hooks and tentacles absent ........... Apionsoma ( Apionsoma ) trichocephalus Sluiter, 1902 – Papillae, hooks and tentacles present, 7–8 basal spinelets ................................................................ .................................................. Apionsoma ( Apionsoma ) hespera ( Chamberlin, 1920 ) comb. nov. 4. Protuberance of the hook streak less than twice the width of the hook .............................................. ................................... Phascolosoma ( Phascolosoma ) puntarenae Grube & Örsted in Grube, 1858 – Hook without protuberance of the hook streak...............................................................................5 5. Hook triangle indistinct or absent; preanal papillae not distinct from dome-shaped trunk papillae ............................................................... Phascolosoma ( Phascolosoma ) agassizii Keferstein, 1866 – Hook triangle well-defined; preanal papillae distinct......................................................................6 6. Preanal papillae dome- to mammiform-shaped at the base of the introvert ....................................... ................................ Phascolosoma ( Phascolosoma ) scolops (Selenka & de Man in Selenka, 1883 ) – Preanal papillae conical, posteriorly directed on the dorsal base of the introvert ......................... ..................................................................... Phascolosoma ( Phascolosoma ) perlucens Baird, 1868