- Clio recurva
- Clione limacina antarctica
- Cliopsis krohni
- Clypeasterophilus stebbingi
- Clytemnestra rostrata
- Clytemnestra scutellata
- Clythrocerus carinatus
- Clythrocerus granulatus
- Clythrocerus moreirai
- Clytia brunescens
- Clytia discoida
- Clytia hemisphaerica
- Clytia lomae
- Clytia noliforme
- Clytia simplex
- Codonaria cistellula
- Codonella amphorella
- Codonella aspera
- Codonella galea
- Codonella nationalis
- Codonella perforata
- Codonella sp.
- Codonellopsis balechi
- Codonellopsis brasiliensis
- Codonellopsis gaussi coxliella
- Codonellopsis gaussi cylindroconica
- Codonellopsis gaussi globosa
- Codonellopsis gaussi typica
- Codonellopsis lusitanica
- Codonellopsis morchella schabi
- Codonellopsis morchella typica
- Codonellopsis obesa
- Codonellopsis orthoceras
- Codonellopsis pusilla
- Coelechinus wapiticornis
- Coelodecas ambulacrum
- Coelodecas pygmaea
- Coelodendrum flabellatum
- Coelodendrum furcatissimum
- Coelodendrum lappaceum
- Coelodendrum ramosissimum
- Coelodendrum spinosissimum
- Coelodiceras spinosum
- Coelographis antarctica
- Coelographis regina
- Coenophthalmus tridentatus
- Cohnilembus verminus
- Coleaspis coronata
- Coleaspis obscura
- Coleaspis vaginata