Aguiiler is certain that no Palaeozoics exist in Mexico except at the borders. Therefore all new land during the Paleozoic. The topography of Mexico is that of young high land. All of the terrain one sees over has been done since the late Tertiary. After the filling of the Cretaceous great lakes some formed as there were drained as London stood back to day after Mercine time. While the Tertiary in considered as a rule it may not be necessary to call in Tertiary Lakes but that the material is an agaded valley material. Aguiiler said that heretofore no canojes can drive from Tehuacan to Jopoteitan. All came by caddle. For one purpose the road has been specifically rerouted to permit canojes to take us to Jopoteitan.