  A one-parameter family of static and spherically symmetric solutions to
Einstein equations with a traceless energy-momentum tensor is found. When the
nonzero parameter $\beta$ lies in the open interval $(0,1)$ one obtains
traversable Lorentzian wormholes. One also obtains naked singularities when
either $\beta < 0$ or $\beta > 1$ and the Schwarzschild black hole for $\beta =
1$.
