Linked below is a set of black and white icons in the older style for hex maps and a map key showing each icon. You can use the pro version of Hexographer to swap them for the existing terrain icons (or to add them as new terrain).
However, they are just a zip of 300x300 pixel transparent PNGs, so if you want to use them with other map software or drawing programs you have permission: http://inkwellideas.com/hexographer_forum/index.php?topic=56.0
More about Hexographer: http://www.inkwellideas.com/roleplaying_tools/hexographer/
Coming soon is another alternate set of color icons for Hexographer and more features, as always!