Callinera, Genus
Carcinonemertes, Genus
Carcinonemertidae, Familia
Carinina, Genus
Carinoma, Genus
Carinomidae, Familia
Cephalothricidae, Familia
Cephalothrix, Genus
Cerebratulidae, Familia
Cerebratulus, Genus
Cestoplana, Genus
Cestoplanidae, Familia
Cestoplanoidea, Superfamilia
Cotylea, Subordo
Craspedommata, Superfamilia
– synonym of Stylochoidea, Superfamilia
Cratenemertidae, Familia
Cryptocelides, Genus
Cryptocelididae, Familia
Cryptocelis, Genus
Cycloporus, Genus