This is a taxonomy of the Kingdom Discicristae.  The taxa are united on the basis of discoid mitochondrial cristae, a character that serves as the source of the name for the group.  Many taxonomic systems use the suffix, -zoa for phylum endings in this group.  I resist its use here because of the "animal" connotation.  In general, however, I have used endings for the higher taxa that conform to Cavalier-Smith (2003).  

CLASS POSTGAARDEA

ORDER POSTGAARDIDA

Postgaardi, Calkinsia.

CLASS DIPLONEMEA

The class has a single order.

Diplonema, Rhynchopus

CLASS EUGLENOIDEA

ORDER DISTIGMIDA (EUTREPTIALES)

Distigma, Eutreptia, Eutreptiella, Distigmopsis.

ORDER EUGLENIDA

Euglena, Ascoglena, Astasia, Khawkinea, Euglenopsis, Cyclidiopsis, Colacium, Hyalophacus, Klebsiella, Lepocinclis, Phacus, Strombomonas, Trachelomonas.

ORDER RHABDOMONADIDA

Rhabdomonas, Rhabdospira, Gyropaigne, Menoidium, Parmidium.

ORDER PERANEMIDA (HETERONEMALES)

Peranema, Heteronema, Peranemopsis, Urceolus, Dinema, Entosiphon.

ORDER SPHENOMONADIDA

Sphenomonas, Atractomonas, Calycimonas, Petalomonas, Tropidoscyphus, Notosolenus, Anisonema.

ORDER EUGLENAMORPHIDA

Euglenamorpha, Hegneria.

CLASS HETEROLOBOSEA

ORDER SCHIZOPYRENIDA

Naeglaria, Tetramitus, Vahlkampfia, Pseudovalkampfia, Heteramoeba, Trimastigamoeba.

ORDER ACRASIDA

Acrasis, Pocheina, Copromyxa, Copromyxella, Guttulina, Guttulinopsis, Fonticula.

ORDER LYROMONADIDA

Lyromonas, Psalteriomonas

CLASS PERCOLATEA

ORDER PERCOLOMONADIDA

Percolomonas

CLASS PSEUDOCILIATEA

ORDER PSEUDOCILIATIDA

Stephanopogon

CLASS DIPHYLLATEA

ORDER DIPHYLLEIDA

Diphylleia (=Aulacomonas), Collodictyon.

CLASS THECOMONADEA

ORDER APNUSOMONADIDA

Apusomonas, Amastigomonas.

ORDER ANCYROMONADIDA

Ancyromonas

ORDER HEMIMASTIGIDA

 Hemimastix, Spironema.