Dolabella gigas? from South Africa

Dear Valda,
This is an interesting find. It is clearly a species of the Sea Hare genus Dolabella but doesn't look at all like the common species Dolabella auricularia. I think it is probably Dolabella gigas, which to my knowledge has never been ilustrated alive. It is reported from the Indian Ocean islands of Mauritius and Reunion and I am pretty sure it has been reported from South Africa. Its shell and armed penis distinguish it from D. auricularia, but published accounts on its external features are rather contradictory. However the conical warts or 'tubercles' in your animal may be a characteristic feature.

The only way to be sure would be to get the shell out of a specimen and have a look at the penis. I have posted alongside Rang's (1828) original illustration of the shell [Plate 3, fig. 4].
Best wishes,
Bill Rudman