A playful "Jungle Bells" theme, complete with lighted monkeys, colorful toucans and water-loving alligators will virtually come to life among the Crystal Bridge's lush, tropical vegetation.    The Crystal Bridge will open free from 6 – 9 p.m. every Sunday in December (except Christmas Eve) for special twilight viewings, courtesy of OG&E.    Myriad Botanical Gardens is located at Reno and Robinson in the heart of downtown Oklahoma City.  For information, call (405) 297-3995 or log on to www.myriadgardens.com.