Hymenocephalus is a genus of rattails.
Species
There are currently 27 recognized species in this genus: Hymenocephalus aeger C. H. Gilbert & C. L. Hubbs, 1920 (Plain-tail whiptail) Hymenocephalus antraeus C. H. Gilbert & Cramer, 1897 Hymenocephalus aterrimus C. H. Gilbert, 1905 (Blackest whiptail) Hymenocephalus barbatulus C. H. Gilbert & C. L. Hubbs, 1920 Hymenocephalus billsam N. B. Marshall & Iwamoto, 1973 Hymenocephalus fuscus P. J. McMillan & Iwamoto, 2014 (Black membranehead) Hymenocephalus grimaldii M. C. W. Weber, 1913 Hymenocephalus hachijoensis Okamura, 1970 Hymenocephalus heterolepis (Alcock, 1889) Hymenocephalus italicus Giglioli, 1884 (Glass-head grenadier) Hymenocephalus iwamotoi Schwarzhans, 2014 (Iwamoto's whiptail) Hymenocephalus lethonemus D. S. Jordan & C. H. Gilbert, 1904 Hymenocephalus longibarbis (Günther, 1887) (Long-barb whiptail) Hymenocephalus longipes H. M. Smith & Radcliffe, 1912 Hymenocephalus maculicaudus P. J. McMillan & Iwamoto, 2014 (Spotty-tail membranehead) Hymenocephalus megalops Iwamoto & Merrett, 1997 (Big-eye whiptail) Hymenocephalus nascens C. H. Gilbert & C. L. Hubbs, 1920 (Nascent membranehead) Hymenocephalus neglectissimus Sazonov & Iwamoto, 1992 Hymenocephalus nesaeae Merrett & Iwamoto, 2000 Hymenocephalus papyraceus D. S. Jordan & C. H. Gilbert, 1904 Hymenocephalus punt Schwarzhans, 2014 Hymenocephalus sazonovi Schwarzhans, 2014 Hymenocephalus semipellucidus Sazonov & Iwamoto, 1992 Hymenocephalus striatissimus D. S. Jordan & C. H. Gilbert, 1904 Hymenocephalus striatulus C. H. Gilbert, 1905 Hymenocephalus torvus H. M. Smith & Radcliffe, 1912 Hymenocephalus yamasakiorum Nakayama, Endo & Schwarzhans, 2015 (Black-tailed membranehead)