and have often wondered what the pitch and dimensions of the pores really are. To partially answer that question, the fourth image is a graph of a trace of the pixel contrast down a row of pores. Using this plot one can find the average distance between the pores (pitch) and the average pore dimensions. The distance is not exact since this is a curved diatom surface and I was approximating it as flat, but the average pore pitch is approximately 500 nm (0.5 micron), and the average pore dimension is approximately 0.46 microns x 0.17 microns.
The last two images are what I think keys out to Cocconeis. As always, please correct my taxonomy.
David
