James R. Snyder has been appointed vice president and branch manager of Legg Mason Wood Walker Inc.'s new office in Largo. He was formerly an investment broker with Legg Mason's Washington office. Robert E. Mathe has been named head of the Washington office of PRC Engineering, one of Planning Research Corp.'s four operating groups. Mathe was formerly with the U.S. Army Corps of Engineers and was Washington, D.C.'s engineer commissioner before the District changed to its present form of government in 1967. Michael F. Greenstone has been appointed sales manager for equities and special projects of Riviere Securities Corp., a Washington investment firm. Bruce W. Podhurst has been promoted to vice president of Edlow International Co., a Washington-based consulting and traffic management firm. Brian E. Schutrumpf has been named senior vice president and manager of investments of Asset Management International, a Washington financial securities management firm. Schutrumpf was formerly director of trust investment research of Riggs National Bank. Joseph P. Banko has been named a principal of Booz-Allen & Hamilton's naval ship systems acquisition practice. Banko was formerly assistant deputy commander for acquisition of the Department of the Navy's naval sea systems command.