Cidaris

Cidaris is a genus of pencil sea urchins.

Species
According to the World Register of Marine Species (WoRMS), the genus Cidaris contains the following extant species
 * Cidaris abyssicola (Agassiz, 1869)
 * Cidaris annulata (Gray, 1855)
 * Cidaris baculosa (Lamarck, 1816)
 * Cidaris blakei (Agassiz 1878)
 * Cidaris cidaris (Linnaeus, 1758)
 * Cidaris mabahissae (Mortensen, 1939)
 * Cidaris nuda (Mortensen, 1903)
 * Cidaris rugosa (Clark, 1907)
 * Cidaris thouarsii (Agassiz & Desor, 1846)

Extinct species or names brought to synonymy

 * †Cidaris aculeata
 * †Cidaris aialensis
 * †Cidaris alpina
 * †Cidaris alternata
 * †Cidaris austriaca
 * †Cidaris avena
 * †Cidaris biconica
 * †Cidaris biformis
 * †Cidaris braunii
 * †Cidaris buchii
 * †Cidaris caudex
 * †Cidaris cingulata
 * †Cidaris coralliophila
 * †Cidaris costalarensis
 * †Cidaris costata
 * †Cidaris costeanensis
 * †Cidaris decorata
 * †Cidaris decoratissima
 * †Cidaris dorsata
 * †Cidaris ecki
 * †Cidaris elegans Munster, 1826
 * †Cidaris elegans Agassiz, 1879, synonym for Histocidaris elegans
 * †Cidaris forminensis
 * †Cidaris fustis
 * †Cidaris glabra
 * †Cidaris hausmanni
 * †Cidaris lanceata
 * †Cidaris linearis
 * †Cidaris milierensis
 * †Cidaris ovata
 * †Cidaris perplexa
 * †Cidaris petersii
 * †Cidaris plana
 * †Cidaris pyramidalis
 * †Cidaris quadrialata
 * †Cidaris quadriserrata
 * †Cidaris regnyi
 * †Cidaris remifera
 * †Cidaris remifera
 * †Cidaris reticulata
 * †Cidaris schwageri
 * †Cidaris scrobiculata
 * †Cidaris seelandica
 * †Cidaris semicostata
 * †Cidaris similis
 * †Cidaris spinachristi
 * †Cidaris spongiosa
 * †Cidaris stipes
 * †Cidaris stoppanii
 * †Cidaris sulcata
 * †Cidaris tenuicostata
 * †Cidaris tetraedrica
 * †Cidaris transversa
 * †Cidaris trapezoidalis
 * †Cidaris trigona
 * †Cidaris triserrata
 * †Cidaris undulatus
 * †Cidaris valparolae
 * †Cidaris verticillata
 * †Cidaris verticillata
 * †Cidaris waechteri
 * †Cidaris wissmanni
 * †Cidaris zardini