SIVER, Peter A., Paul B. HAMILTON, & Eduardo A. MORALES 2007 (June) Notes on the genus Nupela (Bacillariophyceae) including the description of a new species, Nupela scissura sp. nov. and an expanded description of Nupela paludigena Phycol. Res. 55(2): 125-134, 5 figs., 1 table