Seventeen eunicid species from the Grand Caribbean region are characterized, including the description of a new species; fifteen species were collected from Mexican Caribbean coasts; a review of type materials for other six species is also included. The species are
Fauchaldius cyrtauloni Carrera-Parra & Salazar-Vallejo, 1998,
Lysidice ninetta Audouin & Milne-Edwards, 1833,
Marphysa angelensis Fauchald, 1970,
M. angeli Carrera-Parra & Salazar-Vallejo, 1998,
M. aransensis Treadwell, 1939,
M. brevitentaculata Treadwell, 1921,
M. escobarae n. sp.,
M. longula (Ehlers, 1887),
M. minima (Hansen, 1882),
M. posterobranchia Day, 1962,
M. orensanzi Carrera-Parra & Salazar-Vallejo, 1998,
M. regalis Verrill, 1900,
M. sanguinea (Montagu, 1815),
Nematonereis unicornis Grube, 1840, and
Palola siciliensis (Grube, 1840). Type materials of
Lysidice tortugae Treadwell, 1921,
Marphysa aransensis Treadwell, 1939,
M. belli oculata Treadwell, 1921,
M. brevitentaculata Treadwell, 1921,
M. languida Treadwell, 1921, and
M. fragilis Treadwell, 1911 were also reviewed. By a comparison with European specimens,
M. belli oculata is synonymized with the parental form. Furthermore, an analysis of morphological variability of
M. brevitentaculata and
M. sanguinea indicates that current separation of species by the presence of compound setal types should be reviewed. A key for the identification of eunicids (excluding
Eunice) in the Grand Caribbean is also included.