The tube of this genus unquestionably contains a bivalve shell; but, as
no perfect specimen has yet been found, nothing decisive is known
respecting it.
Tube calcareous, thick, conically elongated, more or less flexuous, as
if composed of pieces placed on the ends of each other, or as if
articulated, with a ring or projection more or less marked at the place
of the joints, but without traces of partitions; terminated on one side
by an inflation, oftentimes with some interior partitions, and on the
other by two tubes, distinct and sub-articulated.
_S. arenaria._ The Sand Septaria.
The type of this genus.