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Lejeunecysta lata
Lejeunecysta lata Biffi and Grignani, 1983
Holotype: Biffi and Grignani, 1983, pl. 3, fig. 2, text-fig.2G
Paratypes: Biffi and Grignani, 1983, pl. 3, fig. 1, 4
Locus typicus: Niger Delta, Nigeria
Stratum typicum: Oligocene
Original description: Biffi and Grignani, 1983, p. 134, 136
Diagnosis: Autocyst proximate, peridinioid, compressed dorsoventrally with pentagonal ambitus. Epicyst and hypocyst lengths approximately equal. Epicyst conical, with rounded to slightly acuminate apex. Hypocyst trapezoidal, with two short, pointed antapical horns. Antapical depression low. Cyst sides straight to slightly convex. Autophragm laevigate. Paracingulum rathercontinuous, expressed by two transverse, parallel ridges, sometimes slightly denticular (pl. 3, fig. 4). Hexa archeopyle formed by loss of intercalary 2a, symmetrically situated on middorsal line, extending almost to paracingulum. Dimension: Holotype: autocyst length 109 Ám, breadth 128 Ám. Other specimens: autocyst length 95-110 Ám, breadth 115-130 Ám. 15 specimens measured.
Affinities:
Biffi and Grignani, 1983, p. 136
Remarks: Lejeunecysta lata, n. sp. differs from L. spatiosa in having a laevigate autophragm. It differs from L. fallax in having shorter antapical horns, a low antapical depression, the epicyst-hypocyst lengths approximately equal and in being larger in size. Furthermore their stratigraphic range is different. Lejeunecysta hyalina differs from L. lata, n. sp. in having a wide, deeply excavate paracingulum and a prominent apical horn. Lejeunecysta lata, n. sp. is close to the paratype of L. diversiforma Bradford, 1977 (pl. 4: 6). The main difference seems to be the larger size of L. lata, n. sp., but the specimen figures by Bradford (1977) appears to be oblique and comparison is practically impossible.
Holotype: Biffi and Grignani, 1983, pl. 3, fig. 2, text-fig.2G
Paratypes: Biffi and Grignani, 1983, pl. 3, fig. 1, 4
Locus typicus: Niger Delta, Nigeria
Stratum typicum: Oligocene
Original description: Biffi and Grignani, 1983, p. 134, 136
Diagnosis: Autocyst proximate, peridinioid, compressed dorsoventrally with pentagonal ambitus. Epicyst and hypocyst lengths approximately equal. Epicyst conical, with rounded to slightly acuminate apex. Hypocyst trapezoidal, with two short, pointed antapical horns. Antapical depression low. Cyst sides straight to slightly convex. Autophragm laevigate. Paracingulum rathercontinuous, expressed by two transverse, parallel ridges, sometimes slightly denticular (pl. 3, fig. 4). Hexa archeopyle formed by loss of intercalary 2a, symmetrically situated on middorsal line, extending almost to paracingulum. Dimension: Holotype: autocyst length 109 Ám, breadth 128 Ám. Other specimens: autocyst length 95-110 Ám, breadth 115-130 Ám. 15 specimens measured.
Affinities:
Biffi and Grignani, 1983, p. 136
Remarks: Lejeunecysta lata, n. sp. differs from L. spatiosa in having a laevigate autophragm. It differs from L. fallax in having shorter antapical horns, a low antapical depression, the epicyst-hypocyst lengths approximately equal and in being larger in size. Furthermore their stratigraphic range is different. Lejeunecysta hyalina differs from L. lata, n. sp. in having a wide, deeply excavate paracingulum and a prominent apical horn. Lejeunecysta lata, n. sp. is close to the paratype of L. diversiforma Bradford, 1977 (pl. 4: 6). The main difference seems to be the larger size of L. lata, n. sp., but the specimen figures by Bradford (1977) appears to be oblique and comparison is practically impossible.