Guide to Pinnunavis

Vavles are lanceolate to lanceolate-elliptic. Striae are alveolate and radiate. The raphe is linear with expanded proximal raphe ends. Distal raphe ends are unilaterally hooked. The central area is may be expanded. The striae are open; there are no internal chambers as in Pinnularia and Caloneis, and therefore, no longitudinal lines.

Pinnunavis is a genus with morphological characteristics similar to Navicula and Pinnularia. It is also proposed as a close relative of Caloneis. Pinnunavis has alveoli that are similar in morphology to those of Pinnularia.

Note that "Pinnuavis" is an inadvertent misspelling of the genus name (Moe and Silva 2011). Several species are treated within the genus (Lange-Bertalot and Genkal 1999, Edgar et al. 2015).