  We have analyzed the far-ultraviolet (FUV) spectra of six elliptical and S0
galaxies in order to characterize their hot stellar populations. The spectra
were obtained using the Hopkins Ultraviolet Telescope (HUT) in March 1995.
These data, together with the spectra of two galaxies observed with HUT in
1990, represent the only FUV spectra of early type galaxies that extend to the
Lyman limit at 912 A and therefore include the "turnover" in the spectral
energy distribution below Lyman alpha. Using an extensive new grid of synthetic
spectra which match the HUT resolution and cover the relevant parameter space
of temperature and gravity, we have constructed synthetic spectral energy
distributions by integrating over predicted stellar evolutionary tracks for
horizontal branch stars and their progeny. When the models are compared with
the HUT data, we find that those with supersolar metal abundances and helium
best reproduce the flux across the entire HUT wavelength range, while those
with subsolar Z & Y fit less well, partly because of a significant flux deficit
shortward of 970 A in the models. We find that AGB-Manque evolution is required
in all fits to the HUT spectra, suggesting that all of the galaxies have some
subdwarf B star population. At any Z & Y, the models that best match the HUT
flux are dominated by stars evolving from a narrow range of envelope mass on
the blue end of the horizontal branch.
