Dolabella auricularia -
Shell from Reunion, Indian Ocean, AM C36759. 67mm wide. Photos: Alison Miller.
The shell of Dolabella auricularia is a heavily calcified flattened internal plate which forms a shield-like structure at the posterior end of the body.
I have used this shell from Reunion which has been in the Australian Museum's collection for almost 100 years, because it is so large. At this size, the heavy calcification prevents the shell from drying, cracking and becoming mishapen, which has happened with most of the more recently collected, and smaller shells in the collection.
Rudman, W.B., 2000 (August 30) Dolabella auricularia - Shell. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/dolaaurish