Cultivation of Cryptocoryne nevillii on the long term is not easy. I tried to simulate a dry season by putting the pot out of the water and placing it is a quite humid atmosphere. After some years the plants grow smaller and smaller and finally didn't came back again. Cultivated in beech tree litter it may be easier, the plant easy accepts 'repotting' after the growing period and starts growing again.
Though the locality near Batticaloa is well defined, several collectors couldn't find the plant, even in the wet season. The area may be still unsafe because of minefields?
It is very nice to read the article of Petch from 1928 on this plant. He put his doubt on the - already in his days - misidentification.