Diatomophyceae is a term used to describe a type of phytoplankton characterized by their unique cell walls made of silica. Synonyms for Diatomophyceae include diatoms, Bacillariophyta, and Diatomeae. Diatoms are single-celled algae that can be found in all types of water environments, from freshwater to marine. Bacillariophyta, on the other hand, is a type of algae that can be found in both freshwater and marine environments. Diatomeae is another synonym that has been used to describe these types of algae due to their unique cell structure and reproductive mechanisms. These synonyms are often used interchangeably to describe the same group of organisms.