The title's Penelope is a dolphin secretly taught to talk by an Air Force medical researcher, Captain Williams. Penelope's possibilities are endless. She can be a mine sweeper, a spy on enemy submarines, a spotter for air space capsules and a translator for other fishy critters. (Penelope's speech-breakthrough results in dialogue and dialect that are reminiscent of the minstrel show end man.) This is an Air Force that is like Bilko's Army and Jackie Cooper's Navy. It is peopled with the kind of characters who are better in than out, e.g. Williams' roommate who is a casket company executive and whose best, models transport Penelope to the scenes of her various misadventures. Williams is the most unreceptive male to hit print since Li'l Abner started running away from Daisy Mae. There are occasional word and sight gags that produce an old time, sex-silly laugh in this. Of course, Penelope performs all of her expected functions before she becomes a slippery top-secret and Williams' hormones suddenly blast off when he allows his female research assistant to kiss him. All this rather justifies the publisher's claim that there hasn't been anything quite like this since Thorne Smith. However the book does suggest some ancestors from the more recent past. A possible future is television -- a talking dolphin could be a real splash -- but it is watery wit in print.