Table 1 species list. Antillesomatidae Kawauchi, Sharma & Giribet, 2012 Antillesoma mexicanum Silva-Morales et al, 2019 Panteón Beach, Oaxaca Steinbeck & Ricketts (1941) Aspidosiphonidae Baird, 1868 Aspidosiphon (Akrikos) cf. albus Murina, 1967 – Salazar-Vallejo (1983) A (A.) albus Murina, 1967 Q Cuba Hermoso-Salazar et al. (2013) A. (Aspidosiphon) elegans (Chamisso & Eysenhardt, 1821) Radack, Marshall Islands this study A. (A.) sp. – this study A. (Paraspidosiphon) pastori Silva-Morales & Gómez- Vásquez, 2021 Panteón Beach, Oaxaca this study Golfingiidae Stephen & Edmonds, 1972 Golfingia (Golfingia) cf. muricaudata (Southern, 1913) – this study Nephasoma (Nephasoma) eremita (Sars, 1851) Q NE Norway Fisher (1952) N. (N.) diaphanes (Gerould, 1813) Q E North America Gálvez-Zefrino et al. (2020) N. (N.) laetmophilum Fisher, 1952 San Diego, CA Gálvez-Zefrino et al. (2020) N. (N.) wodjanizkii wodjanizkii (Murina, 1973) Okhotsk Sea, Russia Gálvez-Zefrino et al. (2020) Onchnesoma st. steenstrupii Koren & Danielssen, 1876 Q Bergen, Norway Hermoso-Salazar et al. (2013) Phascolion (Lesenka) salgadoi sp. nov. Guaymas, Sonora this study P. (Phascolion) strombus (Montagu, 1814) Q Devonshire, England Gálvez-Zefrino et al. (2020) Themiste (Themiste) cf. blanda (Selenka et al., 1883) Japan this study T. (T.) hennahi Gray, 1828 Perú Fisher (1952) T. (T.) pyroides (Chamberlin, 1919) Laguna Beach, CA Fisher (1952) Phascolosomatidae Stephen & Edmonds, 1972 Apionsoma (Apionsoma) hespera (Chamberlin, 1920) Laguna Beach, CA Steinbeck & Ricketts (1941) A. (A.) silviae sp. nov. N Gulf of California this study A. (Edmondsius) pectinatum (Keferstein, 1867) Pacific Panama Fisher (1952) A. (E.) hendrickxi sp. nov. N Gulf of California this study Phascolosoma (Phascolosoma) agassizii Keferstein, 1866 Mendocino, CA Steinbeck & Ricketts (1941) P. (P.) perlucens Baird, 1868 Q Jamaica Fisher (1952) P. (P.) puntarenae Grübe & Örsted in Grübe, 1858 Puntarenas, Costa Rica Fisher (1952) Phascolosoma (P.) azteca sp. nov. Los Arcos, Jalisco this study Sipunculidae Rafinesque, 1814 Sipunculus (S.) bastidai sp. nov. W Baja California this study Sipunculus (S.) nudus Linnaeus, 1766 Q “European waters” Steinbeck & Ricketts (1941) Xenosiphon branchiatus (Fischer, 1894) Ecuador Fisher (1947)