| Noun | 1. | Rhodophyceae - coextensive with the Rhodophyta: red algae division Rhodophyta, Rhodophyta - lower plants; mostly marine and littoral eukaryotic algae family Gigartinaceae, Gigartinaceae - a family of protoctist family Rhodymeniaceae, Rhodymeniaceae - a family of protoctist Bangiaceae, family Bangiaceae - a family of protoctist class - (biology) a taxonomic group containing one or more orders |