>_>
you devious person you. Why you no tell us all the rules before someone answers?
Also, not to sound mean or anything but.....
I do not really believe I gave an answer. I just asked a question about the question. In fact, I just made a statement that I was under the impression all of them Evolved, which they do. And I was talking about the current as well just so you know. Besides, I just checked Serebii, and the only ghost pokemon that only have one evolution are Spiritomb, Sableye and Shedinja. And they are not pure ghost types.
Yamask evolves into Cofagrigus,
Duskull evolves into Dusclops then into Dusknoir,
Shuppet evolves into Banette,
and Misdreavus evolves into Mismagius,
So they, in fact, do all evolve.
So please, tell me which pure ghost type does not evolve.