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

Navicula approximata f. elongataHustedt image
Navicula approximata f. manca(A.W.F. Schmidt) Hustedt image
Navicula approximata f. morei(O'Meara) Hustedt image
Navicula approximata f. typicaCleve image
Navicula approximataGreville Edinburgh New Philos. J. ser. 2, 10: 28, pl. IV: fig. 4 1859
Navicula approximata var. couperi(Bailey) Cleve K. Svenska Vet.-Akad. Handl., ser. 4, 27{3}: 63 1895
Navicula approximata var. finitima(Cleve) Hustedt image
Navicula approximata var. kittoniana(A. Schmidt) Cleve image
Navicula approximata var. mexicanaHeiden image
Navicula approximata var. nicaensis_('niceaensis')(Peragallo) Hendey J. Roy. Micr. Soc., ser. 3, 77: 63 1957
Navicula approximata var. sardoaV. Zanon Bollettino di pesca, piscicoltura e idrobiologia 3: 218, text-fig. 3 1948
Navicula approximata var. schleinitzii(Janisch) Hustedt image
Navicula approximata var. substauroneiformisGrunow in A. Schmidt Atlas Diat.: pl. 2: figs. 20, 21 1874