Hystrichosphaeridium macrotubulum Neale and Sarjeant, 1962

Originally Hystrichosphaeridium, subsequently Oligosphaeridium, thirdly Oligosphaeridium?.
Tax. jr. synonym of Hystrichosphaeridium (now Oligosphaeridium) vasiformum Neale and Sarjeant, 1962, according to McIntyre and Brideaux, 1980
Holotype: Neale and Sarjeant, 1962, pl.20, fig.7, text-fig.8a
Locus typicus: Speeton Clay, Heslerton, England
Stratum typicum: Hauterivian

Original diagnosis: Neale and Sarjeant, 1962, p. 452
A species of Hystrichosphaeridium having an ovoidal to sub-quadrate shell with a coarsely granular surface. The tubes connect directly to the shell interior and are open distally. They vary in thickness but are typically massive, tapering somewhat at base and tip but elsewhere or constant diameter. They open outwards at their distal extremity, giving rise to processes variable in number (2-6) and length
but always pointed. Length of the tubes constantly greater than the smallest shell cross-measurement. No pylome developed.

Original description: Neale and Sarjeant, 1962, p. 453
Shell and spines pale yellowish-brown. Tubes very finely and irregularly perforate, frequently with a large lateral opening just above their base on one side and always with root-like extensions on the surface. The distal branches vary greatly in length and direction with relation to the shell surface. Number of tubes 18-24.
Dimensions: Type; overall 122 x 116 µm, shell 46.5 x 38 µm, spines 43.5-49 µm in length. Range: Overall (max.) 100-120 µm.