NEW YORK, Dec 18-(/P) -Lea* ty Art Larsen a- cat Leandro,Calif,, and Mrs.:Hairgarfct;Osborne Dupont are the _ nation s No. 1 amateur tennis players for 1950.The stormy petrel from toe Pacific Coast and the steady matron from Wilmington, De., headed National ratings announced over ti e weekend by ranking committees of the tJ. S. Lawn Tennis Association.The rankings still must be a proved by the USLTA general meeting here next month but this is routine.The trigger - temepered Larsen becomes the first Southpaw swinger to lead the country'sracquet brigade since Jc-iinny Doeg was supreme in 1930.He swept through the upset* studded National champion * ships at Forest Hills, defeating Herb lam of Beverly Hills, Calif., in the finals.Flam won the No. 2 position in the ranking followed by Budge Patty of Los Angeles and Ted Schroeder of a La Crescents, Calif, Schroeder was rated No, 2 last year behind Pancho Gonzales, who later turned pro. Patty spent most of his timein Europe and it figuered in the1949 list.Mrs. DuPont’s top positionfollowedJier third straight National championship. She turned back Doris Hart of Jacksonville, Fla., 6-3, 6-3, in the finals at Forest Hills.• •Miss Hart was No. 2 in the.wo* men’s rankings, which produced two new faces. They were Nancy Chaffee of Ventura, Calif., surprise winner over Wimbledon Champion Louise Brough at Forest Hills, No, £ and Maureen Conndlly of San Diego, Calif., No. 10.Althea Gibson of New York, the first Negro to play in * the outdoor Nationals* failed tm? %e the first twenty -fdSsipw^- J** strong stand in an'~ early match against Miss Brough-bufc she*rated mention in a antedtel^SBEhs *group. *Billy Talbert of New York and Tony Trabert of Cincinnati were named the No. 1 men’s doubles team. Mrs. DuPont arid* Miss Brough took the same honor among the ladies, J-V S'Z*■' * ......... 1 _i - - j7 *