Crustumius? A lost city of Rome?

L Sprague De Camp, in his non-fiction article “Lost Cities”, refers to a city named Crustumius, allegedly lost beneath a sea.

Online, I find the name, but it refers to a region, or to a river.

Which would make a kind of sense, if an ancient city in the region had been destroyed.
All references I find suggest it is a Roman-era name.

Can anybody tell me about Crustumius?

Could it be referred-to by a different name?

De Camp preferred old terminology, & could be a tad prolix. I wouldn’t put it past him to use an archaic name, now obsolete.

Input?

The only Crustumius I can find is a river.

Dictionary of Greek and Roman Geography (1854) William Smith, LLD, Ed.

So the river, now called the Conca, was given to flooding, and someone once mistakenly asserted there was a town of the same name at its mouth. I think we’ve run this one down.

Likely.
My thanks.

The only ancient city I can think of which is claimed to have sunk is one mentioned by either Herodotus or Thucydides. Hekkale, was it?

Perhaps it was Crustumerium, an ancient town of the Sabines north of Rome. Crustumerius was the adjective form of the name. The site of the town was once considered lost but was rediscovered in the 1970s.

Correction: It was a Latin town near Sabine territory, not a Sabine town.

An aly spelling!

Hmmm–any legends of all or part of it being flooded, or submerged, or lost to the sea by landslide?