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

Nitzschia subtilis(Kützing) Grunow image
Nitzschia subtilis f. tchadensisCompère image
Nitzschia subtilis var. acicularisFrenguelli image
Nitzschia subtilis var. genuinaMayer image
Nitzschia subtilis var. glacialisGrunow image
Nitzschia subtilis var. paleaceaGrunow image