Suborder (2) Microthoracina Jankowski, 1967

Syns.

Cyrtopharyngina, Microthoracida

Hypostomial frange reduced drastically to (or replaced by?) a few short kinetal segments bearing "pseudomembranelles" and sometimes set in a shallow atrium; body, frequently broadly ellipsoidal (with right side more rounded), occasionally crescentic, and often laterally flattened, with firm pellicle and sparsely ciliated; fibrous trichocysts (fibrocysts) present; species typically fresh-water or edaphic, often cyst-forming; but the enigmatic Discotricha is marine.

Three "pseudomembranelles" on left side of oral area and stomatogenesis parakinetal- or even buccokinetal-like.	Family LEPTOPHARYNGIDAE Kahl, 1926
With characteristics of suborder s.s. (above); but Discotricha dorsoventrally flattened, etc.	Family MICROTHORACIDAE Wrzesniowski, 1870