Medusozoans from the Mexican Pacific: a review based on historical literature and recent observations Author Estrada-González, Mariae C. Author Agüero, José Author Mendoza-Becerril, María A. text Journal of Natural History 2023 2023-06-15 57 1 784 853 http://dx.doi.org/10.1080/00222933.2023.2214967 journal article 60720 10.1080/00222933.2023.2214967 a9bb27e7-4ac2-4b5e-928e-9d8985ea179a 1464-5262 8224400 Pasya quadridentata (Ellis and Solander, 1786) ( Figure 7K, L ) Material examined Several colonies, polyp, with gonophores; Punta Los Muertos , Baja California Sur , 24.248°, 110.150°W; depth 1–2 m ; 20 July 2018 ; on the alga Codium simulans ; ECO-CH-Z 11762 . Identification (after Calder 1991 ; Miranda et al. 2011 ) Colonies erect; hydrocaulus monosiphonic, unbranched, divided into internodes by distinct oblique nodes. Basal athecate internodes separated from the thecate internodes by an oblique node; thecate internodes with 1–3 pairs of opposite hydrothecae. Hydrothecae contiguous and continuous in front of internodes, separated across back. Proximal pair of a group curved outwards with hydrothecal axes oblique to internodal axis, distal pair more straight; adnate parts of adcauline wall straight, free part convex; abcauline wall concave except for basal part. Hydrothecal margin with two large rounded lateral cusps and a smaller median adcauline cusp. Operculum formed by two valves, a large abcauline and a smaller adcauline. Gonotheca with six rounded, transverse ridges, arising by short pedicels from hydrocaulus just beneath the hydrotheca on the first thecate internode. Distribution Previously recorded on the west coast of the Gulf of California , Baja California ( Fraser 1938c ), making it a new record for the south-western gulf in Baja California Sur . In the MP, it has been recorded from Baja California and Baja California Sur ( Fraser 1938a , 1948 ). Remarks The specimen fits the descriptions of the species Dynamena quadridentata . However, this paper maintains the assignment to the genus Pasya , based on robust molecular evidence ( Moura et al . 2011 ) and the historical nomenclature of the taxon ( Calder 2013 ). The genus Pasya requires revision to clarify its taxonomic status.