The University of Missouri-Columbia says it has $25 million from anonymous donors who want a new basketball arena built. But it won’t happen unless the legislature kicks in another $35 million. Curators have voted to ask the legislature to authorize a bond issue for that money. The school has had plans for an arena seating 17,500 sitting on a shelf since Bill and Nancy Laurie offered, then withdrew, a $10 million donation for a new arena.