Terebratula is a valid Brachiopod genus.  However I believe the west coast
species transversa is a Terebratalia (sometimes listed under Terebratella),
not a Terebratula.  Terebratula species tend to be more inflated and smooth.
They are in fact the forms that the name "lamp shell" derives from.
Terebratalia and Terebratella do not resemble lamps very much, but some
Terabratula do indeed look a lot like an old oil lamp.
Paul M.