Paraclevelandia brevis in ‘simplex’ form

(Figs 23H–P, 24C, F; Supporting Information, Tables S30–S33)

When present, the simplex form was present in low to moderate abundance.

Description based on ASS, PAA and STH in vivo,andPAA, STH, and SRU in protargol preparations: Medium-sized Clevelandellidae (on average 84 × 47 µm in vivo, range 70–101 × 38–58 µm; on average 76 × 45 in protargol preparations, range 61–98 × 37–53 µm). Ovate to almost broadly fusiform, anterior end tapers to rounded point, posterior end broadly rounded, peristomial projection absent as in ‘brevis’ form; distinct left lobe absent. Macronucleus elongated, cylindrical, situated longitudinally in anterior half of cell near right cell margin. Micronucleus oval, near midportion of macronucleus, smaller compared to brevis form (3.4 vs. 5.3 µm). A sack-like structure formed between anterior margin of macronucleus and anterior end of cell as reported by Kidder (1937, 1938), visible both in vivo (Fig. 23H, I) and protargol preparations (Fig. 23J). Karyophore inconspicuous, not visible in vivo, sometimes visible in protargol preparations (Fig. 23J, O), attached to both anterior and posterior end of macronucleus. Cortex with refractile interkinetal granules, probably mucocysts (Fig. 23I). Somatic ciliature in same pattern and distribution as ‘brevis’ form. Kinetal furrows conspicuous. Up to 20 free kinetofragments in right suture (Fig. 23K, P). Organization of oral ciliature as for the family with same exceptions as ‘brevis’ form. Adoral zone narrows from posterior to anterior, extends about 50% of cell length on average, composed of an average of 28 membranelles (range 25–32).