Conuber incei 
Copse Snail 
Coptocheilus sectilabris 
Coriocella hibyae 
Corona incisa 
Coryphellina arveloi 
Coryphellina flamma 
Coryphellina lotos 
Costasiella formicaria 
Costasiella fridae 
Costasiella kuroshimae 
Costasiella usagi 
Cratena affinis 
Cratena simba 
Cratena Slug 
Craven Door-Snail 
Crenavolva aureola 
Crested Mudalia 
Crested Nembrotha 
Cristataria haasi 
Crowned Nudibranch 
Cryptozona bistrialis 
Cupedora bednalli 
Cuspivolva formosa