Sulmo

SULMO(Sermoneta), an ancient city of Latium, mentioned only by Pliny (Plin. Nat. 3.5. s. 9) among those which were extinct in his time, and incidentally noticed by Virgil. ( Aen. 10.517.) It is in all probability the same place with the modern Sermoneta, which stands on a hill between Norba and Setia, looking over the Pontine Marshes.
[E.H.B]