Hemipneustidae is an extinct family of sea urchins. Genera Hemipneustes L. Agassiz, 1835 † Medjesia Jeffery, 1997 † Opisopneustes Gauthier, 1889 † Plesiohemipneustes Smith & Wright, 2003 † Toxopatagus Pomel, 1883 † References Holasteroida