Silva Center for Phycological Documentation: Index Nominum Algarum

The INA is a card file and online reporting system maintained at the Silva Center for Phycological Documentation of the University Herbarium, University of California, Berkeley. It contains nearly 200,000 names of algae (in the broad sense). The BPU is a card file containing bibliographic references pertaining to algal taxonomy.
A working list of algal type specimens at UC is available here

Results from INA database

Helosphaeridium echinodermum(Stockmans & Willière) G.L. Mullins Journal of Micropalaeontology 21: 91 2002
HELOSPHAERIDIUMLister Palaeontogr. Soc. [London] Publ. 528: 76 1970
Helosphaeridium clavispinulosumLister image
Helosphaeridium latispinosumLister image
Helosphaeridium pseudodictyumLister image