Looks like wendtii to me. They can look very different depending onhow and where they're grown. The same plant can have small leaves all clumped tightly or it can be a foot tall. They can be green or brown. It all depends on light and nutrients.
They might be different species but it's not impossible they're all the same plant.
I know it's hard to identify crypts, that's why I asked for help. But if i'm sure of something it's that these are not ALL different forms of wendtii. For sure picture three and six are not, I might guess that six is a crypt petchii . Has for the others they might well be different forms of wendt. They grow in a similar fashion and have sensibly the same leaf structure.
If any one else has any ideas or opinions please tell me.