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Hystrichosphaerina varians
Hystrichosphaerina varians (May, 1980) Lentin and Williams, 1981
Originally Systematophora, subsequently (and now) Hystrichosphaerina.
Holotype: May, 1980, pl.7, fig.12-14
Locus typicus: Atlantic Highlands, New Jersey
Stratum typicum: Campanian
Original description: May, 1980, p.69: Systematophora varians
Cyst main body ovoidal. Bilayered; endophragm appears baculate (bacula ca. 1 Ám long), thicker (ca. 1.5 Ám thick) than periphragm; (ca. 1.0 Ám thick) periphragm micro- to macroreticulate over cyst main body, also formed into highly variable simulate process groups. Each process group is supported proximally by a broad-based simulate sutural ridge, and is composed of well-spaced, somewhat vertically arranged, simple to compound, slender, stringlike processes. A "simulate" network of simple or compound trabeculae connect the distal tips of the processes of each process group. Both the processes and trabeculae are similar in construction, appearing as simple or compound stringlike elements; the compound elements being separate, anastomosing, reticulate, or fused into porous, membranelike elements. Lateral and polar process groups appear longest. The average height of process groups varies greatly (a few to ca. 17 Ám) from specimen to specimen: specimens at both extremes appearing morphologically quite different at first glance, especially when process groups of very low relief blend in with the highly variable, reticulate surface of the periphragm. Process arrangement suggests a reflected tabulation of ?", 6", 5--6c, 5""", ?1p, 1"""", ?s. Cingular process groups are poorly to well-developed, appear simulate, and are elongate in the direction of the cingulum. Cingulum levorotatory, having ca. 1 cingulum width offset. Sulcus located beneath midventrally alignecl sulcal notch of the archeopyle, and bears an undetermined number of poorly developed sulcal processes. Archeopyle apical (Type A); opercula not observed.
Discussion: Although most specimens observed are identifiable as Systematophora Klement 1960, a great degree of variability exists in the height and development of the process groups. Dorsoventral process groups which are not as well-developed as the lateral and polar process groups, are often reduced in height, and may be nearly lacking, giving a distinctive Cyclonephelium appearance. Other specimens bear reduced process groups marginally and dorso-ventrally, appearing vaguely as Cyclonephelium and distinctively different from Systematophora. The assignment of this form into Systematophora was based on the morphology of most specimens, which bear simulate (sometimes appearing annulate) process groups reflecting Gonyaulax-type tabulation, and exhibiting an apical archeopyle (Type A).
Dimensions: Holotype--Main body 74 x 70 Ám; process length 12--16 Ám. Observed range (11 specimens measured): main body length 56--74 Ám; width 67--87 Ám; process length 3--17 Ám; wall layers, endophragm ca. 1.5 Ám, periphragm less than 1 Ám.
Affinities:
May, 1980, p.69: Systematophora varians
S. varians is similar to S. schindewolfii (Alberti) Downie and Sarjeant 1965 and S. complicata Neale and Sarjeanat 1962. S. schindewolfii, however, has longer process groups which expand distally, and are rather constricted proximally S. complicata bears process groups of rather small base, and individual process groups are composed of numerous, long, simple spines, which are joined distally by branches or trabeculae. S. varians, has broad-based process groups and much more variability in process and trabeculum structure.
Originally Systematophora, subsequently (and now) Hystrichosphaerina.
Holotype: May, 1980, pl.7, fig.12-14
Locus typicus: Atlantic Highlands, New Jersey
Stratum typicum: Campanian
Original description: May, 1980, p.69: Systematophora varians
Cyst main body ovoidal. Bilayered; endophragm appears baculate (bacula ca. 1 Ám long), thicker (ca. 1.5 Ám thick) than periphragm; (ca. 1.0 Ám thick) periphragm micro- to macroreticulate over cyst main body, also formed into highly variable simulate process groups. Each process group is supported proximally by a broad-based simulate sutural ridge, and is composed of well-spaced, somewhat vertically arranged, simple to compound, slender, stringlike processes. A "simulate" network of simple or compound trabeculae connect the distal tips of the processes of each process group. Both the processes and trabeculae are similar in construction, appearing as simple or compound stringlike elements; the compound elements being separate, anastomosing, reticulate, or fused into porous, membranelike elements. Lateral and polar process groups appear longest. The average height of process groups varies greatly (a few to ca. 17 Ám) from specimen to specimen: specimens at both extremes appearing morphologically quite different at first glance, especially when process groups of very low relief blend in with the highly variable, reticulate surface of the periphragm. Process arrangement suggests a reflected tabulation of ?", 6", 5--6c, 5""", ?1p, 1"""", ?s. Cingular process groups are poorly to well-developed, appear simulate, and are elongate in the direction of the cingulum. Cingulum levorotatory, having ca. 1 cingulum width offset. Sulcus located beneath midventrally alignecl sulcal notch of the archeopyle, and bears an undetermined number of poorly developed sulcal processes. Archeopyle apical (Type A); opercula not observed.
Discussion: Although most specimens observed are identifiable as Systematophora Klement 1960, a great degree of variability exists in the height and development of the process groups. Dorsoventral process groups which are not as well-developed as the lateral and polar process groups, are often reduced in height, and may be nearly lacking, giving a distinctive Cyclonephelium appearance. Other specimens bear reduced process groups marginally and dorso-ventrally, appearing vaguely as Cyclonephelium and distinctively different from Systematophora. The assignment of this form into Systematophora was based on the morphology of most specimens, which bear simulate (sometimes appearing annulate) process groups reflecting Gonyaulax-type tabulation, and exhibiting an apical archeopyle (Type A).
Dimensions: Holotype--Main body 74 x 70 Ám; process length 12--16 Ám. Observed range (11 specimens measured): main body length 56--74 Ám; width 67--87 Ám; process length 3--17 Ám; wall layers, endophragm ca. 1.5 Ám, periphragm less than 1 Ám.
Affinities:
May, 1980, p.69: Systematophora varians
S. varians is similar to S. schindewolfii (Alberti) Downie and Sarjeant 1965 and S. complicata Neale and Sarjeanat 1962. S. schindewolfii, however, has longer process groups which expand distally, and are rather constricted proximally S. complicata bears process groups of rather small base, and individual process groups are composed of numerous, long, simple spines, which are joined distally by branches or trabeculae. S. varians, has broad-based process groups and much more variability in process and trabeculum structure.