Hydrolagus
Hydrolagus is a genus of fish in the family Chimaeridae found in the Atlantic, Indian and Pacific Oceans. Species
The 22 recognized species in this genus are:
 Hydrolagus affinis (Brito Capello (pt), 1868) (small-eyed rabbitfish)
 Hydrolagus africanus (Gilchrist, 1922) (African chimaera) 
 Hydrolagus alberti Bigelow & Schroeder, 1951 (gulf chimaera)
 Hydrolagus alphus Quaranta, Didier, Long & Ebert, 2006 (whitespot ghost shark)
 Hydrolagus barbouri (Garman, 1908)  (ninespot chimaera)
 Hydrolagus bemisi Didier, 2002 (pale ghostshark)
 Hydrolagus colliei (G. T. Lay & E. T. Bennett, 1839) (spotted ratfish)
 Hydrolagus eidolon D. S. Jordan & C. L. Hubbs, 1925
 Hydrolagus erithacus Walovich, Ebert & Kemper, 2017 (Robin's ghostshark) 
 Hydrolagus homonycteris Didier, 2008 (black ghostshark)
 Hydrolagus lusitanicus T. Moura, I. M. R. Figueiredo, Bordalo-Machado, A. C. Almeida & Serrano-Gordo, 2005 (Portuguese chimaera)
 Hydrolagus macrophthalmus F. de Buen, 1959 (bigeye chimaera)
 Hydrolagus marmoratus Didier, 2008 (marbled ghost shark)
 Hydrolagus matallanasi Soto & Vooren, 2004 (striped rabbitfish)
 Hydrolagus mccoskeri L. A. K. Barnett, Didier, Long & Ebert, 2006 (Galápagos ghostshark)
 Hydrolagus melanophasma K. C. James, Ebert, Long & Didier, 2009 (Eastern Pacific black ghostshark)
 Hydrolagus mirabilis (Collett, 1904) (large-eyed rabbitfish)
 Hydrolagus mitsukurii (D. S. Jordan & Snyder, 1904) (Mitsukuri's chimaera)
 Hydrolagus novaezealandiae (Fowler, 1911) (dark ghostshark)
 Hydrolagus pallidus Hardy & Stehmann, 1990 (pale chimaera)
 Hydrolagus purpurescens (C. H. Gilbert, 1905) (purple chimaera)
 Hydrolagus trolli Didier & Séret (fr), 2002 (abyssal ghostshark)
Fossil remains of the genus are known from the Miocene and Pliocene of California. 