Back
Xandarodinium xanthum
Xandarodinium xanthum Reid, 1977
Matsuoka, 1984, and Lewis et al., 1984, considered this species to represent the encysted stage of Protoperidinium divaricatum (Meunier, 1919) Parke and Dodge, 1976.
Holotype: Reid, 1977, pl.3, fig.27-28
Stratum typicum: Recent
Locus typicus: Dee Estuary, North Sea, England
Original description: Reid, 1977, p. 447-448
Diagnosis: A species of Xandarodinium with a concave ventral area and convex dorsal area. Wall thin with a smooth surface. Processes have elliptical circular or elongate bases in plan view; from as extensions from the wall, and are terminated by simple spines or multifurcate extensions. Ventral surface and anterior dorsal surface, smooth and not ornamented by processes.
Dimensions: Holotype, test 56x56 µm, process height 6 µm. Range, test, 46x46-48x63 µm, process height, 5-19 µm. 15 specimens measured.
Description (annotated): The processes ornamenting the cyst may be simple, circular or complex flanges with multifurcate tips. Dorsal processes are intratabular, aligned equatorially reflecting the cingulum and intercalary plates. A small process complex is found at the anterior end of the ventral area and the apical plates are reflected by three processes. A complex of processes is found on two low antapical bosses with a shallow depression connecting them. Processes are not found on the operculum of the archeopyle. The cyst has a characteristical pale yellow-brown colour and was seen in certain specimens to contain a thin hyaline layer.
Affinities:
Reid, 1977, p. 447
This species is similar to the illustration of the cyst of Protoperidinium minutum (Kofoid) Loeblich by Wall and Dale (1968). It differs in having a smooth and not corrugated surface, and in not being spherical.
Matsuoka, 1984, and Lewis et al., 1984, considered this species to represent the encysted stage of Protoperidinium divaricatum (Meunier, 1919) Parke and Dodge, 1976.
Holotype: Reid, 1977, pl.3, fig.27-28
Stratum typicum: Recent
Locus typicus: Dee Estuary, North Sea, England
Original description: Reid, 1977, p. 447-448
Diagnosis: A species of Xandarodinium with a concave ventral area and convex dorsal area. Wall thin with a smooth surface. Processes have elliptical circular or elongate bases in plan view; from as extensions from the wall, and are terminated by simple spines or multifurcate extensions. Ventral surface and anterior dorsal surface, smooth and not ornamented by processes.
Dimensions: Holotype, test 56x56 µm, process height 6 µm. Range, test, 46x46-48x63 µm, process height, 5-19 µm. 15 specimens measured.
Description (annotated): The processes ornamenting the cyst may be simple, circular or complex flanges with multifurcate tips. Dorsal processes are intratabular, aligned equatorially reflecting the cingulum and intercalary plates. A small process complex is found at the anterior end of the ventral area and the apical plates are reflected by three processes. A complex of processes is found on two low antapical bosses with a shallow depression connecting them. Processes are not found on the operculum of the archeopyle. The cyst has a characteristical pale yellow-brown colour and was seen in certain specimens to contain a thin hyaline layer.
Affinities:
Reid, 1977, p. 447
This species is similar to the illustration of the cyst of Protoperidinium minutum (Kofoid) Loeblich by Wall and Dale (1968). It differs in having a smooth and not corrugated surface, and in not being spherical.