I was very conformable calling all
> in the family terebra until I read the "Living Terebras of the World"
> and found they (authors Bratcher & Cernoohorsky) break the family into
> the genera: Terebra, Duplicaria, Hastula (with subgenus Impages), and
> Terenolla.  They also list 41 or so previous genus and subgenus name
> applied to this family.
Katsura Oyama published several papers on the Terebras; the most accessible
is in Venus (1961 : vol. 21 (2) : 176-189). I saw him give a talk on the
family some years back, in which he divided them into genera based on the
anatomy of the foregut and mouth. He raised dozens of genera for the
Terebridae during his career, including Brevimyurella, Cinguloterebra,
Clathroterebra, Decorihastula, Granuliterebra, Hastulopsis, Laeviacus and
Pristiterebra. Anyone for whom Bratcher and Cernohorsky is not complicated
enough should investigate Oyama's work. Personally, I prefer B&C.