<i>Tetrakeronopsis silvanetoi</i>.

<p><b>A–D.</b> Schematic diagrams representing the ciliature organization of <i>T. silvanetoi</i> after protargol-impregnation. <b>A.</b> Detail of anterior region of body showing frontal and oral ciliatures. The black arrowhead points to anteriormost midventral cirral pair, and the white arrowheads show a gap in the lapel adoral membranelles; <b>B.</b> Detail of dorsal side showing anterior dorsal ciliature; <b>C.</b> Ventral ciliature; <b>D.</b> Dorsal ciliature; <b>E–G.</b> Live organism. <b>E.</b> Specimen showing habitus. Arrowhead points to adoral zone; <b>F.</b> Cytoplasmic inclusions. Black arrowheads mark ring-shaped bodies; white arrowheads mark globular bodies. <b>G</b>. Detail of cortical granules (arrowheads). Legend: AZM – adoral zone (of membranelles); BC – buccal cirrus; DK – dorsal kineties; E – endoral; FC(n) – frontal cirrus; FTC – frontoterminal cirri; PBC(n) – parabuccal cirrus; LMR – left marginal cirral row; MV – midventral complex; P – paroral; PTC – pretransverse cirri; RMR – right marginal cirral row; TC – transverse cirri. Scale bars: <b>C–D</b>. 60 µm; <b>F–G</b>. 4 µm.</p

Electron and optical micrographs of <i>Tetrakeronopsis silvanetoi</i>.

<p><b>A.</b> Scanning electron microscopy image showing aspects of anterior region of body. Asterisk marks peristomal lip; black arrowheads point to dorsal bristles; white arrowheads show longitudinal ventral groove; <b>B–H.</b> Specimens after protargol-impregnation. <b>B.</b> Ventral side of specimen showing detail of infundibular fibers (black arrowheads). The white arrowhead shows buccal cirrus; <b>C.</b> Detail of anterior region of body after protargol-impregnation; <b>D.</b> Posterior ventral region, showing transverse ciliature; <b>E.</b> Posterior termini of dorsal kineties. The arrowhead indicates the terminus of right dorsal kinety; <b>F.</b> Detail of adoral zone showing gaps in lapel membranelles (arrowheads); <b>G.</b> Detail of anterior region of body, dorsal side. The black arrowheads show dorsal kineties, and the white arrowhead indicates the gap which splits the adoral zone; <b>H.</b> Detail of dorsolaterally placed adoral membranelles in the distal region of lapel (white arrowhead) and the crown adoral membranelles (black arrowhead). Legend: AZM – adoral zone (of membranelles); BC – buccal cirrus; E – endoral; FC(n) – frontal cirrus; FTC – frontoterminal cirri; PBC(n) – parabuccal cirrus; LMR – left marginal cirral row; MV – midventral complex; P – paroral; PTC – pretransverse cirri; RMR – right marginal cirral row; TC – transverse cirri. Scale bars: <b>A.</b> 10 µm; <b>B–H.</b> 20 µm.</p

Morphometric characterization of <i>Tetrakeronopsis silvanetoi</i> gen. nov., sp. nov.

<p>Legend: AM – adoral membranelles; AZM – adoral zone (of membranelles); CV – coefficient of variation; DK1– left dorsal kinety; DK2– middle dorsal kinety; DK3– right dorsal kinety; LMR – left marginal cirral row; M – median; Max – maximum value observed; Mean – arithmetic mean; Min – minimum value observed; N – sample size; RMR – right marginal cirral row; SD – standard deviation; SE – standard error.</p

Distance matrix of 18S-rDNA sequences of representatives of the Pseudokeronopsidae.

<p>Distance matrix of 18S-rDNA sequences of representatives of the Pseudokeronopsidae.</p

Part of the analyzed nucleotide matrix containing the Pseudokeronopsidae and showing the positions that are identity markers for the Nothoholostichinae subfam.

<p>nov. (rectangle) within the context of studied data. NCBI/GenBank accession codes are displayed left of species names.</p

Morphological comparison among genera of the Nothoholostichinae subfam. nov.

<p>Morphological comparison among genera of the Nothoholostichinae subfam. nov.</p

Photomicrographs of <i>Apoamphisiella vernalis</i> from Minad Gerais after protargol-impregnation, showing stages of divisional morphogenesis.

<p>(A) and (B) Ventral side of middle-to-late divider showing anlagen for proter (A) and opisthe (B). Arrowheads mark surplus transverse cirri in the proter (notice that surplus transverse cirri are also present in the opisthe, but out of focus in the image). (C) Middle divider showing dorsal kineties anlagen for the proter (white arrowheads) and opisthe (black arrowheads). (D) Fragmentation of right dorsal anlagen (arrows) and formation of caudal cirri (arrowheads). Anlagen labeled with roman numbers, where “o” names the opisthe and “p” names the proter.</p

Uncorrected <i>P</i>-distances among the terminals in the cluster of the “non-stylonychine dorsomarginalians” in which <i>A</i>. <i>vernalis</i> was placed.

<p>Uncorrected <i>P</i>-distances among the terminals in the cluster of the “non-stylonychine dorsomarginalians” in which <i>A</i>. <i>vernalis</i> was placed.</p

Photomicrograhps of <i>Apoamphisiella vernalis</i> after protargol-impregnation, showing stages of divisional morphogenesis of ventral side.

<p>(A) Opisthe of middle divider showing left (white asterisk) and right (black asterisk) marginal rows anlagen and dorsomarginal kineties anlagen (arrow). (B) Detail of juvenile dorsomarginal kineties (arrow) of opisthe. (C) Proter of late divider showing juvenile fronto-ventral-transverse cirri linked according to anlagen. Black arrowhead shows transverse cirrus formed by extra anlage. (D) Late divider showing distribution of juvenile macronuclear nodules in proter (white asterisks) and opisthe (black asterisks). Ma = macronuclear nodule; Mi = micronucleus.</p

Diagram showing homologies among ventral cirri of <i>Cyrtohymena</i>, European and North American <i>Paraurostyla weissei</i>, and <i>Apoamphisiella</i> on stylized drawings.

<p>*The rightmost ventral cirral row of European <i>P</i>. <i>weissei</i> corresponds to the posterior segment of an amphisiellid row. Fronto-ventral-transverse anlagen are numbered in romans. IV_? = anlage supposedly related to IV; V_i … V_j = serial homology of anlage V, where “i” is the leftmost and “j” the rightmost in the series; aAR = anterior segment of the amphisiellid cirral row; B = buccal; F = frontal; FV = frontoventral; Pp = postperistomal; PT = pretransverse; T = transverse; VR = ventral cirral row; - = inapplicable.</p