  Using the derived gamma-ray burst E_peak and fluences from the complete BATSE
5B Spectral Catalog, we study the ensemble characteristics of the
E_peak-fluence relation for GRBs. This relation appears to be a physically
meaningful and insightful fundamental discriminator between long and short
bursts. We discuss the results of the lower limit test of the E_peak-E_iso
relations in the E_peak-fluence plane for BATSE bursts with no observed
redshift. Our results confirm the presence of two GRB classes as well as
heavily suggesting two different GRB progenitor types.
