  The excitation function for the 7 alpha de-excitation of $^{28}$Si nuclei
excited to high excitation energies in the collisions of 35 MeV/nucleon
$^{28}$Si with $^{12}$C reveals resonance structures that may indicate the
population of high spin toroidal isomers such as those predicted by a number of
recent theoretical calculations. This interpretation is supported by extended
theoretical analyses.
