Okada & McIntyre 1977
After Young et al. 2003. Smaller than H. carteri, narrow flange, small wing; central area closed or with two small inline pores; blanket elements confined to central area and a weak ridge often surrounds them. Coccospheres 10-13 μm, liths 4-5 μm.
Southern Ocean, south of Australia.
HOL - unknown, but Geisen et al. (in press) speculate that S. ponticuliferus in a likely candidate.