[2] If treated as an alga, it would fall under the International Code of Botanical Nomenclature (ICBN) and its correct name would be Euglenaceae; if treated under the International Code of Zoological Nomenclature (ICZN) it is called Euglenidae.

[1] Two genera, Strombomonas and Trachelomonas produce outer shells called loricae.

[4] As with other euglenids, cells in the Euglenaceae are surrounded by a series of proteinaceous strips called the pellicle; the pellicle can stretch in most genera, allowing the cell to contract, creating a type of movement called metaboly.

[1] Chloroplasts are diverse in this family, with the size, shape, number, and presence of pyrenoids being important identifying characteristics.

[4] Its sister family is Phacaceae, which contains several genera (Lepocinclis, Phacus, and Discoplastis) formerly included within Euglenaceae.