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Muderongia sp. b of davey 1982b

Muderongia sp. B of Davey 1982b
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Genus: Muderongia Cookson and Eisenack, 1958; emend. Monteil, 1991
tax. sr. synonym of Phoberocysta Millioud, 1969, according to Monteil, 1991.
tax. sr. synonym of Pseudomuderongia Jain and Khowaja-Ateequzzaman, 1984, according to Helby, 1987, and Stover and Williams, 1987.
Type species: Muderongia macwhaei Cookson and Eisenack, 1958; emend. Helby, 1987

Original description: Cookson and Eisenack 1958, p.40
Diagnosis: Test flattened, bilaterally symmetrical, composed of a thin outer membrane and an internal body or capsule. The outer membranes prolonged into four equidistant horns and crossed by a narrow shallow girdle. A longitudinal furrow is not developed.

Stover and Evitt 1978, p. 66-67
Synopsis: Cysts proximate, generally cornucavate, body ceratioid with an apical, two cingular, and two antapical horns, of which one may be reduced or absent; proximal part of cingular horns in line with paracingulum, distal part directed antapically; periphragm smooth or weakly ornamented; archeopyle apical, Type tA; parasulcal notch offset.
Modified description:
Shape: Ceratioid; generally rhomboidal with an apical, two cingular, and two unequally developed antapical horns. Proximal part of cingular horns straight and in line with paracingulum, distal part directed antapically; the two parts commonly form an obtuse angle, and a short projection is typically
present at the apex of the angle.
Wall relationships: Cysts generally cornucavate; a narrow antapical pericoel may be present.
Wall features: Parasutural features commonly absent; faint parasutural lines, low ridges, or ornamentation present on some species. Periphragm smooth or ornamented with scabrae or small spines; endophragm smooth or scabrate.
Paratabulation: Indicated by archeopyle, occasionally also by faint parasutural features; formula: 4", 6"", 6c, 6""", 1p, 1""".
Archeopyle: Apical, Type tA; principal archeopyle suture zigzag; parasulcal notch offset; operculum free.
Paracingulum: Position indicated by cingular horns; other indications generally lacking or expressed as faint, parallel, transverse lines.
Parasulcus: Generally not indicated.
Size: Intermediate to large.

Emended description: Monteil, 1991, p. 40-471
Synopsis: Cysts proximate to proximochorate, compressed dorsoventrally, two-layered, cornucavate to circumcavate; pericyst ceratioid, asymmetrical or symmetrical, with usually 5 or 4 prominent horns: 1 apical, 2 lateral and 2 or 1 antapical; endocyst oval to rhombic or pentangular. Periphragm bearing processes or not. Gonyaulacacean paratabulation rarely completely indicated by low ornamental features or by processes; formula ?pr, 4", 0a, (sic, 6"" missing here,) 6c, 6""", 1"""", 1p, 3s (with rs, ls and ps fused). Archaeopyle apical, type (4A).
Emended diagnosis:
Shape: Cysts proximate to proximochorate, compressed dorsoventrally. Pericyst ceratioid, asymmetrical or symmetrical, with usually 5 or 4 prominent horns: 1 apical (Type AP I), 2 lateral (Types L I, II or IV) and 2 antapical (Types ATP I, II or III), the right one being always reduced or absent. Horns indented or not, normal or tapered, with distal extremities closed, rounded or pointed, sometimes perforated-scalloped or perforated-ragged. Proximal extremities ofhorns narrow or wide; endocyst oval to rhombic, sometimeswith eccentric antapex extending in the left antapical horn, or pentangular, sometimes with a protrusion at the base of the horns or stretching out up to the middle part of the five horns.
Wall relationships: Cysts two-layered, cornucavate to delphicavate or circumcavate.
Wall features: Periphragm thin, psilate to scabrate, sometimes folded, microperforate, perfortae, spinous, or bearing processes; endophragm thin, psilate to granulate.
Archaeopyle: Apical, type (4A), angular margin; parasulcal notch marked. Operculum free.
Paratabulation: Indicated by archaeopyle and sometimes by low ridges or septa, and rarely by verrucae, by folds of periphragm and/or finely perforated areas. Formula: ?pr, 4", 0a, 6"", 6c, 6""", 1"""", 1p, 3s (with rs, ls and ps fused). fm (De Cruz and Monteil, in progress). More or less clearly expressed by distribution and type of processes (stages I to IV), when those are present.
Pericingulum: Marked by indentation of lateral horns and, generally, by parallel transverse structures. Endocingulum not observed.
Perisulcus: Marked by parasulcal notch offset, appearing sinuous when discernable. Exceptionally, perisulcal area clearly subdivided. Endosulcus not observed.
Size: Intermediate to large, length of pericyst 85-260 Ám.
Affinities:
Stover and Evitt 1978, p. 66-67
Muderongia differs from Phoberocysta in having a smooth to weakly ornamented periphragm, whereas the periphragm on Phoberocysta is ornamented with numerous irregularly shaped processes.

Monteil, 1991, p. 471: Muderongia differs from Odontochitina and Xenascus in having 5 or 4 horns rather than 3.
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