The Urban Underclass: Challenging THe Myths ABout America's Urban Poor Paul Peterson and Christopher Jencks, co editors of "The Urban Underclass," and William Julius Wilson, a contributor to the book, will conduct a public symposium from 2 to 4 p.m. Tuesday, April 16, in the Brookings auditorium. Discussants will include James Johnson of UCLA, Charles Murray of the American Enterprise Institute and Isabel Sawhill of the Urban Institute. The conference is open to press and other interested parties. If you plan to attend, please call 202/797 6105. _______________