Figure 2 in The search finds an end: the morphologically chimeric hysterocinetids belong to the subclass Hymenostomatia (Ciliophora: Oligohymenophorea)

Figure 2. Protoptychostomum simplex in vivo (A, B) and asser protargol impregnation (C–I). A, detail of the anterior body region, showing densely arranged basal bodies of somatic kineties and the unciliated V-shaped sucker lined by regularly spaced, oblique rows of highly refractive granules. B, detail of the posterior body region, showing the oral ciliature and the vacuolized cytoplasm. C, D, less-side overviews, showing the variability of body shape and size, as well as of the nuclear apparatus. E, F, I, details of the infundibular and peristomial ciliature, as well as of the nuclear apparatus, which is composed of an ellipsoidal macronucleus and two globular micronuclei. Arrowhead in (E, F) marks the curved anterior end of membranelles M1 and M2. G, somatic kineties are composed of narrowly spaced monokinetids. Asterisks mark irregularities in the somatic ciliary paưern. H, surface view, showing cortical granules. CP, cytopharynx; F, fibre; G, granules; M1–2, membranelle 1 and 2; MA, macronucleus; MI, micronuclei; OA, oral apparatus; OC, oral cilia; PM, paroral membrane; S, sucker; SK, somatic kineties. Scale bars = 5 µm (I), 10 µm (F, G), 15 µm (A, B), 40 µm (E), 50 µm (C, D).