The walls of some algae differ, e.g. the silica boxes enclosing diatoms, and the calcareous layer on the cell walls of calcareous algae.

• 一些藻类的细胞壁的化学成分有所不同，例如硅藻属的细胞壁含有硅化物，石灰质藻类的细胞壁含有钙。