Varro, L.L. 5.157
Livy 5.40 (Gallic Sack of Rome): While all this was going on [sc. evacuation of the city], the Flamen of Quirinus and the Vestal virgins, without giving a thought to their own property, were deliberating as to which of the sacred things they ought to take with them, and which to leave behind, since they had not strength enough to carry all, and also what place would be the safest for their custody. They thought best to conceal what they could not take in earthen jars (doliolis) and bury them under the chapel next to the Flamen’s house, where spitting is now forbidden. The rest they divided amongst them and carried off, taking the road which leads by the Pons Sublicius to the Janiculum. Whilst ascending that hill they were seen by L. Albinius, a Roman plebeian who with the rest of the crowd who were unfit for war was leaving the City. Even in that critical hour the distinction between sacred and profane was not forgotten. He had his wife and children with him in a wagon, and it seemed to him an act of impiety for him and his family to be seen in a vehicle whilst the national priests should be trudging along on foot, bearing the sacred vessels (publicas sacra) of Rome. He ordered his wife and children to get down, put the virgins and their sacred burden in the wagon, and drove them to Caere, their destination.
Festus, s.v. doliola – the place of Rome so named, because at the time when the Gauls invaded the city, the sacred objects were placed in this place, and enclosed in barrels. For this reason, it was forbidden even to spit in this place.