Ca
- Cactosoma
- Calamactinia
- Calamactis
- Calamphora
- Calcigorgia
- Calibelemnon
- Calicogorgia
- Calliactis
- Callicarpa
- Callipodium
- Callogorgia
- Callozostron
- Calpasoma
- Calvinia
- Calycella
- Calycopsis
- Calyptopora
- Calyptrophora
- Caminothujaria
- Campanularia
- Campanulariidae
- Campanulina
- Campanulinidae
- Canarya
- Candelabridae
- Candelabrum
- Candidella
- Cannorhiza
- Cannota
- Cantharellus
- Capnella
- Carcinactis
Cardianecta Pugh, 2016
- Cardianecta parchelion Pugh, 2016
Cnidaria → Hydrozoa → Siphonophorae → Cordagalmatidae
- Caribisis
- Carijoa
- Carlgrenia
- Carotalcyon
- Carpocladus
- Carukia
- Carybdea
- Carybdeidae
- Caryophyllia
- Caryophylliidae
- Cassiopea
- Cassiopeidae
- Catablema
- Catalaphyllia
- Cataphellia
- Catostylidae
- Catostylus
- Caulastraea
- Caulastrea
- Cavernularia
- Cavernulina
Ce
- Ceeceenus
- Cephea
- Cepheidae
- Ceratocaulon
- Ceratocymba
- Ceratotrochus
- Cereus
- Ceriantharia
- Ceriantheomorphe
- Ceriantheopsis
- Cerianthidae
- Cerianthula
- Cerianthus
- Cervera
- Cespitularia
Ch
- Chalcogorgia
- Charisea
- Charisella
- Chathamisis
- Cheiloporidion
- Chelidonisis
- Chelophyes
- Chiarella
- Chirodectes
- Chirodropida
- Chirodropidae
- Chirodropus
- Chironephthya
- Chironex
- Chiropsalmidae
- Chiropsalmus
- Chiropsella
- Chiropsoides
- Chondronephthya
- Chondrophellia
- Choriactis
- Chromatonema
- Chromonephthea
- Chromoplexaura
- Chrysaora
- Chrysogorgia
- Chrysogorgiidae
- Chrysopathes
- Chunella
- Chunellidae
- Chuniphyes
Ci
- Circinisis
- Cirrhipathes
- Cirrhitiara
- Cirrholovenia
- Cirrholoveniidae
Cl
- Cladacanthella
- Cladactella
- Cladangia
- Cladiella
- Cladocarpoides
- Cladocarpus
- Cladocora
- Cladocoryne
- Cladocorynidae
- Cladonema
- Cladonematidae
- Cladopathes
- Cladopathidae
- Cladoplumaria
- Cladopsammia
- Cladosarsia
- Clathrozoella
- Clathrozoellidae
- Clathrozoidae
- Clathrozoon
- Clausophyes
- Clausophyidae
- Clava
- Clavactinia
- Clavularia
- Clavulariidae
- Climacocodon
- Clytia
Cn
- Cnidanthus
Koljeno Cnidaria Verrill, 1865;Žarnjaci
- Anthozoa Ehrenberg, 1834, koralji
- Cnidaria incertae sedis
- Cubozoa Werner, 1973,
- Hydrozoa Owen, 1843, obrubnjaci
- Myxozoa
- Scyphozoa Götte, 1887, režnjaci
- Staurozoa Marques & Collins, 2004
- Polypodiozoa Raikova, 1994
Biota → Eukaryota → Unikonta → Opisthokonta → Animalia → Eumetazoa → Radiata
- Cnidocodon
- Cnidopus
- Cnidostoma
Co
- Codonium
- Coelogorgia
- Coelogorgiidae
- Coeloseris
- Coenocyathus
- Coenosmilia
- Colangia
- Colobonema
- Colpophyllia
- Concentrotheca
- Condylactis
- Condylanthidae
- Condylanthus
- Confluphyllia
- Conocyathus
- Conopora
- Conotrochus
- Convexella
- Coralliidae
- Corallimorpharia
- Corallimorphidae
- Corallimorphus
- Corallium
Cordagalma Totton, 1932
- Cordagalma abyssorum Pugh, 2016
- Cordagalma bimaculatum Pugh, 2016
- Cordagalma isocarrei Pugh, 2016
- Cordagalma ordinatum (Haeckel, 1888)
- Cordagalma rugosum Pugh, 2016
- Cordagalma tottoni Margulis, 1993
Cnidaria → Hydrozoa → Siphonophorae → Physonectae → Cordagalmatidae
Porodica Cordagalmatidae Pugh, 2016
- Cardianecta Pugh, 2016
- Cordagalma Totton, 1932
Cnidaria → Hydrozoa → Siphonophorae → Physonectae
- Cordylophora
- Cordylophoridae
- Corhiza
- Cornularia
- Cornulariidae
- Coronatae
- Coronephthya
- Corydendrium
- Corymorpha
- Corymorphidae
- Corynactis
- Coryne
- Corynidae
- Coscinaraea
- Cosmetira
- Cosmetirella
- Cotylorhiza
Cr
- Cradactis
- Crambione
- Crambionella
- Craseoa
- Craspedacusta
- Crassophyllum
- Crateritheca
- Craterolophus
- Cribrinopsis
- Cricophorus
- Crispatotrochus
Crossota Vanhöffen, 1902
- Crossota alba Bigelow, 1913
- Crossota brunnea Vanhöffen, 1902
- Crossota millsae Thuesen, 2003
- Crossota norvegica Vanhöffen, 1902
- Crossota rufobrunnea (Kramp, 1913)
Cnidaria → Hydrozoa → Trachymedusae → Rhopalonematidae
- Cryogorgia
- Crypthelia
- Cryptodendrum
- Cryptohydra
- Cryptolarella
- Cryptolaria
- Cryptophyton
- Cryptotrochus
- Crystallophyes
Cs
- Csiromedusa
- Csiromedusidae
Ct
- Ctenactis
- Ctenella
- Ctenocella
Cu
- Cubaia
Cubomedusae
- Prihvaćeno kao Carybdeida
Razred Cubozoa Werner, 1973
- Red: Carybdeida Claus, 1886
- Red: Chirodropida
*Red: Cubomedusae = Carybdeida Animalia → Cnidaria
†Cuifastraea Melnikova 1983
- †Cuifastraea arthaberi Haas 1909
- †Cuifastraea granulata Melnikova 1983
- †Cuifastraea lopatensis Turnsek and Kosir 2000
Cnidaria → Anthozoa → Scleractinia → Archaeofungiina → Cuifastraeidae
†Porodica Cuifastraeidae Melnikova 1983
- Rodovi: Cuifastraea, Gillastraea, Silesiastraea, Tropiphyllum
Cnidaria → Anthozoa → Scleractinia → Archaeofungiina
- Culicia
- Cunina
- Cuninidae
- Cupressopathes
- Cuspidella
- Cuvieria
Cy
- Cyananthea
- Cyanea
- Cyaneidae
- Cyathelia
- Cyathopodium
- Cyathotrochus
- Cyclocanna
- Cyclohelia
- Cyclomuricea
- Cylicia
- Cynarina
- Cyphastrea
Podred Cystonectae Haeckel, 1887
- Physaliidae Brandt, 1835
- Rhizophysidae Brandt, 1835
Cnidaria → Hydrozoa → Hydroidolina → Siphonophorae
- Cytaeididae
- Cytaeis