Pl.: fistulae

A pipe or conduit; in baths, it was often made of lead. Many fistulae carry the names of the craftspeople who made them, the workshops that produced them, and/or even the ultimate owners of the structure into which the pipes were laid.

L: A lead fistula in situ in the baths at Bath, UK. Note the fold on the right hand side of the pipe (Photo Andrew Dunn, Wikimedia Commons; CC BY SA 2.0).
R: a fragment of lead fistula (L: 37.5 cm) stamped in the name of the emperor Vespasian (Inv. L-1033-60; Courtesy of the Penn Museum).