Sept. 16, 1961 - A large-scale round-up of Roman Catholic priests has taken place in Havana in the last two days. There are no precise figures, but roughly 100 priests have been arrested. The Government will deport some, if not all, of these. In another development, the execution of six persons in various parts of Cuba for participation in armed seditious activity was announced. Ninety-one received prison terms ranging from one to thirty years. The new executions bring to 16 the number of foes of the Castro regime who have faced firing squads this month.