| Synonym/Old Name | New Name | Taxonomy Group | ||
|---|---|---|---|---|
 | Corallina elongata | Ellisolandia elongata | Rhodophyta | more info |
 | Corallina fragilissima | Amphiroa fragilissima | Rhodophyta | more info |
 | Corallopsis durvillei | Gracilaria durvillei | Rhodophyta | more info |
 | Crassiphycus birdiae | Gracilaria birdiae | Rhodophyta | more info |
 | Crassiphycus firmus | Gracilaria firma | Rhodophyta | more info |
 | Crocosphaera watsonii | Cyanobium waterburyi | Cyanobacteria | more info |
 | Cryptonemia lomation | Cryptonemia palmetta | Rhodophyta | more info |
 | Cylindrotheca gerstenbergeri | Cylindrotheca gracilis | Bacillariophyceae | more info |
 | Cymbella microcephala | Encyonopsis microcephala | Bacillariophyceae | more info |
 | Cystoclonium armatum | Chondrus armatus | Rhodophyta | more info |
 | Cystoseira abies-marina | Gongolaria abies-marina | Phaeophyceae | more info |
 | Cystoseira baccata | Gongolaria baccata | Phaeophyceae | more info |
 | Cystoseira banksii | Hormosira banksii | Phaeophyceae | more info |
 | Cystoseira barbata | Gongolaria barbata | Phaeophyceae | more info |
 | Cystoseira hakodatensis | Stephanocystis hakodatensis | Phaeophyceae | more info |
 | Cystoseira indica | Polycladia indica | Phaeophyceae | more info |
 | Cystoseira latifrons | Hormophysa cuneiformis | Phaeophyceae | more info |
 | Cystoseira nodicaulis | Gongolaria nodicaulis | Phaeophyceae | more info |
 | Cystoseira osmundacea | Stephanocystis osmundacea | Phaeophyceae | more info |
 | Cystoseira sedoides | Ericaria sedoides | Phaeophyceae | more info |
Credits to Prof Leonel Pereira
