  The wavefronts from a point source in a solid with cubic symmetry are
examined with particular attention paid to the contribution from the conical
points of the slowness surface. An asymptotic solution is developed that is
uniform across the edge of the cone in real space, the interior of which
contains the plane lid wavefront analyzed by Burridge \cite{Burridge67}. The
uniform solution also contains the regular wavefronts away from the cone edge,
a delta pulse on one side and its Hilbert transform on the other. In the
direction of the cone edge the three wavefronts merge to produce a singularity
of the form $H(t) t^{-3/4}$.
