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

SPIRODISCUSEhrenberg image
Spirodiscus capitatus(Wolle) Kuntze image
Spirodiscus circinatus(Wolle) Kuntze image
Spirodiscus cochlearisEichwald image
Spirodiscus crassispinis(Reinsch) Kuntze image
Spirodiscus cuspidatus(Bailey) Kuntze image
Spirodiscus flexuosus_('flexuosa')(Ehrenberg) Woodhead & Tweed image
Spirodiscus fulvusEhrenberg image
Spirodiscus lunula(Reinsch) Kuntze image
Spirodiscus major(Naegeli) Kuntze image
Spirodiscus obesusJurilj Prir. Istr. 26: 165, no fig. 1954
Spirodiscus parvulus(Perty) Kuntze image
Spirodiscus spiralis(Kützing) Jurilj image
Spirodiscus viridisEichwald image