  The Plancherel formula for the universal covering group of $SL(2, R)$ derived
earlier by Pukanszky on which Herb and Wolf build their Plancherel theorem for
general semisimple groups is reconsidered. It is shown that a set of unitarily
equivalent representations is treated by these authors as distinct.
Identification of this equivalence results in a Plancherel measure
($s\mathrm{Re}\tanh\pi(s+\frac{i\tau}{2}), 0\leq\tau<1)$ which is different
from the Pukanszky-Herb-Wolf measure ($s\mathrm{Re}\tanh\pi(s+i\tau),
0\leq\tau<1)$.
