I may be able to help here Phoenix.
Just give me till tomorrow when I get home and compare with mine that are growing emersed.Im Away from home tonight.
I think alan is correct in saying they loo likt they have been grown emersed.
Where did you come by these? Dont want actual names, but did you get through work? or from anothe hobbiest?
Most crypts will do well in low to medium lighting and as Alan said, most prefer acid conditions, except a few as named.
Crypts will melt usually when they are exposed to changing conditions, ie temp ,ph or the roots are disturbed.
In saying that, I Have a bunch that are moved regularly from tank to tank with only lead weight and they still manage to survive and not 'melt'.
They seem to do better when planted into a mature tank
They are heavy root feeders, so plonk a couple of JBL 7 Balls in with them and leave them, only removing leaves as the melt.
it may seem as though all hope is gone, but leave them and in no time if they are happy will grow back twice as large.
I LOVE CRYPTS
PS, If you dont want them, PM me and I will take em
Will get back to you with ID