Lissodelphys gen. nov. Diagnosis. Body elongate, cylindrical, vermiform, and unsegmented, narrowing anteriorly and posteriorly. Body surface smooth, lacking ornamentation of setules or spinules. Rostrum distinct. Antennule small, lobate, unsegmented. Antenna 2- or 3-segmented, with unsegmented endopod bearing small terminal claw. Labrum uncertain. Mouthparts consisting of mandible, maxillule, maxilla, and maxilliped. Mandible consisting of coxa and biramous palp; coxa gnathobase narrow with pectinate medial margin; palp obscurely segmented, armed with 4 setae on outer lobe (exopod) and 5 setae on inner lobe (basis + endopod). Maxillule obscurely 2-segmented (precoxa and palp) or unsegmented; armedwith 6 to 8 setae. Maxilla unsegmented or incompletely 2-segmented; armed with 5 setae. Maxilliped as small lobe bearing few setae.All setae of mouthparts naked. Legs absent. *Abbreviations and symbols: A2, antenna; Mnd, mandible; Mx1, maxillule; Mx2, maxilla; Mxp, maxilliped; +, present; X, absent. Type species. Lissodelphys guadeloupensis gen. et sp. nov. by original designation. Other included species. Lissodelphys tahitiensis gen. etsp. nov. Etymology. The name is derived from liss (Greek meaning “smooth”), the prefix of the generic name of the host of the type species, Lissoclinum fragile (Van Name, 1902), and - delphys, the ending of many generic names in the Notodelphyidae. Remarks. Lissodelphys gen. nov. appears to be closely related to the genus Pythodelphys in sharing a similarly elongate, vermiform body and a pectinate coxal gnathobase on the mandible. However, the new genus can be separated from Pythodelphys because the urosome is unsegmented and completely fused with the prosome, the body surface is smooth (densely setulose in Pythodelphys), the maxilliped is distinct (vestigial or absent in Pythodelphys), and the maxilla is 1- or 2- segmented (distinctly 4-segmented in Pythodelphys). The differences between Lissodelphys gen. nov. and other vermiform genera of the Notodelphyidae that lack legs are summarised in Table 13.

Published as part of Kim, Il-Hoi & Boxshall, Geoff A., 2020, Untold diversity: the astonishing species richness of the Notodelphyidae (Copepoda: Cyclopoida), a family of symbiotic copepods associated with ascidians (Tunicata), pp. 1-6 in Megataxa 4 (1) on pages 627-628, DOI: 10.11646/megataxa.4.1.1, http://zenodo.org/record/4591138