Are Still MissingBy LEE BYRDAssociated Press WriterKENSINGTON, Md. (AP) —Fifteen days after their 13-and 11-year-old daughters went out for some pizzas and did not return, John and Mary Lyon still await the call that could end their ordeal in either grief orjoy.The case of the missing Sheila and Kate Lyon has attracted massive publicity in the nation’s capital. It also has baffled the best minds of the area’s law enforcement agencies, including the FBI.Search parties have long since combed miles around the Lyons’ suburban home. Divers have dragged the area’s waters. Specially trained dogs have been flown in only to lose the scent. And scores upon scores of tips, ranging from hunches to purported sightings, have been reported by well-meaning citizens but to no avail.Police are virtually convinced the two blonde youngsters are not runaways. For one thing, they’re too young to have been gone so long without being reported. For another, their home, by all indications, was a happy one.The girls, on the first day of their Easter vacation from school, walked out the front door and headed up a flagstone path through the woods to a nearby shopping center.“I said to them, Why don’t you stop off and get some pizza.’ recalls Mrs. Lyon. “I remember Kate complained that a slice of pizza used to be 40 cents and now it’s 45 cents.”By 8 p.m., We were really scared” and her husband called the police, she said. “They took us seriously right from thestart.”One leading theory is that the girls were abducted by a 50-to BO-year-old man who was seen tape recording a conversation with them on a bench outside the pizza parlor early in the afternoon of the day they disappeared.The most striking of hundreds of unconfirmed leads came Monday, when a motorist in Manassas, Va., 30 miles from Kensington, reported seeing a station wagon driven by a man whose description matched that of the suspect — with two girls the witness thought were tied up in the back seat.But police couldn’t find any such car despite flooding the roads with patrol vehicles. At least 400 citizen band radio operators also roamed the Virginia suburbs without finding the station wagon.