  The dispersionless limit of generalized Drinfeld-Sokolov hierarchies
associated to primitive regular conjugacy class of Weyl group W(g) is
discussed. The map from these generalized Drinfeld - Sokolov hierarchies to
algebraic solutions to WDVV equations has been constructed. Finite dimensional
geometry behind hierarchies is studied.
  Example of g=D_4 and [w]=D_4(a_1) is considered in details and corresponding
Frobenius structure is found.
