Is this Tamanovalva or Berthelinia?

Dear Nishina,
As I said in my answer to Atsushi Ono, the question of which generic name to use is very difficult to decide. Personally I have difficulty in using the fossil name Berthelinia, as we have no way of determining if the animals that made the fossil shells are really closely related to any living species. The situation is further complicated because it is possible that that Edenttellina typica, which is the earliest name for a living species may be congeneric with Tamanovalva. I don't think there is any purpose in just assuming that all these species are congeneric so my feeling is that we should continue to call this animal Tamanovalva limax until an anatomical review of the living species is conducted. That is why I have continued to use Midorigai and Edenttellina for the Australian species. Without evidence it is no more sensible to say they are the same as it is to say they are different. As I said earlier, I would welcome some other opinions on this.
Best wishes,
Bill Rudman.