Dear Gijs;-
        OK! I'm easily convinced---in almost any direction.
        What the Oliva/Olivella brings up to me is this question: Is there a
formula for separation of families? In other words: how different and in
what respect must the differences be to split a family?
        Now that I think of it, the same question might be asked of Genera and
Species. It would be nice to have some sort of chart that could quantify
the quality of differences. It is asking for the simplification of
something that is not at all simple. But it would help us to understand
better why an Afgan Hound and a Pomeranian are more similar than an
Olive and an Ollivella.
        Interesting discussion.
        Art