Photosynthetic cells, usually pigmented green or brown.
Cells amoeboid, moving by deformations of the cytoplasm. Extrusions of the cytoplasm are called pseudopodia, and may be either tubular (lobed, cylindrical) or filose (thin and thread-like). Without cilia or flagella.
At least partly covered in cilia, which may be evenly distributed across cell body or localized to certain parts, and even arranged into specialized structures. Cell body can be rigid or deformable.
Cells with a few (usually 1 or 2) long flagella. Cell body can be rigid or deformable.
Cell bodies spherical, with radially-arranged axopods, long and rigid structures involved in prey capture. Easily confused with some filose amoebae.
Some instances of protists interacting with each other and other organisms.