Such a gorgeous Phal! I am taking a wild guess here - Phal philippinensis?
I really would reconsider planting this beauty into a Terrarium. I would be afraid of rotten roots in this moist environment. This one begs to swing gently in a gentle breeze with lots of aeration.
If you are still looking to plant Orchids into a terrarium, how about looking into small Pleurothallid species( and also installing a small computer fan into it.)
I should add - if we are talking about a large Wardian Case, then please disregard my comment!
