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Micrhystridium Deflandrei
Original description: [Valensi, 1949, p. 545-546] (translated form French):
Micrhystridium Deflandrei nov. sp.
3 to 5 of fig. 5.
Holotype: Lower Bathonian, flint from Airvault (Deux-Sèvres).
The shell (3 of fig. 5) strictly spherical is covered in an extremely regular manner, with fine piliform processes, the length and spacing of which are everywhere equal. On the upper face the points which correspond to their insertion are distributed in parallel rows interrupting towards the equator and then resuming with a different direction.
On the lower face (5 of fig. 5) they are arranged in parallel rows, the whole constituting a very characteristic diamond-shaped grid which is not without recalling that of certain valves of Diatoms. The optical section (4 of fig. 5) shows the equality of length of the processes, at least in the zone where fossilization has not damaged them. The color of all the specimens observed is dark brown.
In the holotype, the diameter is 11 μ, the length of the processes of 1 μ; another specimen, found in a flint from the same locality and the same level, measures 13 μ in diameter. The Lower Bathonian of Airvault provided me with some debris of this species unknown in both the Silurian and the Cretaceous.
Micrhystridium Deflandrei nov. sp.
3 to 5 of fig. 5.
Holotype: Lower Bathonian, flint from Airvault (Deux-Sèvres).
The shell (3 of fig. 5) strictly spherical is covered in an extremely regular manner, with fine piliform processes, the length and spacing of which are everywhere equal. On the upper face the points which correspond to their insertion are distributed in parallel rows interrupting towards the equator and then resuming with a different direction.
On the lower face (5 of fig. 5) they are arranged in parallel rows, the whole constituting a very characteristic diamond-shaped grid which is not without recalling that of certain valves of Diatoms. The optical section (4 of fig. 5) shows the equality of length of the processes, at least in the zone where fossilization has not damaged them. The color of all the specimens observed is dark brown.
In the holotype, the diameter is 11 μ, the length of the processes of 1 μ; another specimen, found in a flint from the same locality and the same level, measures 13 μ in diameter. The Lower Bathonian of Airvault provided me with some debris of this species unknown in both the Silurian and the Cretaceous.