Euglenoids, such as Euglena, do not have a rigid cell wall like plants or fungi. Instead, they possess a flexible layer called a pellicle.

Composition: The pellicle is a protein-rich (proteinaceous) layer located just beneath the plasma membrane.

Structure: It consists of protein strips arranged in a helical pattern, supported by microtubules.

Function: These strips can slide over one another, a process known as metaboly, which gives euglenoids their characteristic flexibility and ability to change shape.