Ah! This must be one of our Danish friends. Microsorium is coming along great. Slow growing, but it looks really good. Unfortunatley it's doing better than the Crypts right now. I'm thinking about trying it on a slab of EpiWeb inthe back of my main tank. Sort of like a moss wall effect.
Actually, in person it doesn't look anything like Bolbitis heteroclita. The leaf tissue is much narrower along the veins, say a uniform 3/8 inch width. Even along the midrib.
It looks more like a terrestrial Pteris multifida.