Not my specimen, but this is a perfect example of D. bennettii.
Again, not my specimen, but this is a perfect example of Donponoxylon jacksonii.
Again not my specimen, but this one closely resembles the original Pentoxylon from India.
This example of D. bennettii was discarded by another collector who obviously did not realise it's rarity. It has been overlaid with a sheet of acetate and marked to show the growths and their centres.
This large specimen is probably D. jacksonii. A small specimen, poorly preserved,