>1.  How many species of the marine clam, Fimbria, live today?  And where does/do it/they live?  And does anyone know if the Eocene fossil species called Fimbria are really the same genus as the Recent?<

I think there are two species currently recognized, though that is a general recollection rather than an authoritative pronouncement.  Living Fimbria are Indo-Pacific.  I do not know of any significant difference between the living and fossil species that would warrant a genus separation.  Fimbriidae reportedly occurs back to the Carboniferous, so it is a rather conservative lineage.

>3.  The stromboid, Terebellum, is called Seraphs in some of the fossil literature.  Are they really different?<

Peter Jung monographed the group, I think in Palaeontographical Americana.  In this, he discusses differences between the genera, including Seraphs and Terebellum.  Terebellum is the only living genus in this group.

    Dr. David Campbell
    Old Seashells
    University of Alabama
    Biodiversity & Systematics
    Dept. Biological Sciences
    Box 870345
    Tuscaloosa, AL  35487-0345 USA
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That is Uncle Joe, taken in the masonic regalia of a Grand Exalted Periwinkle of the Mystic Order of Whelks-P.G. Wodehouse, Romance at Droitgate Spa