As workers in the extensional terrances of southern Nevada, we welcome the recent paper by Campagna and Aydin <1994> in which they use field and geophysical evidence to interpret the geometry and genesis of basins in southern Nevada. In our opinion, however, their analysis of the significance of their data for the structural evolution of the region is inadequate and potentially misleading to the casual reader because they fail to discuss relevant concepts and literature. Below we address our three principal criticisms of their paper and thus provide an opportunity for Campagna and Aydin to clarify several assertions that are puzzling to us. ¿ American Geophysical Union 1995