The volunteer slaves were enlisted into the nineteenth and twentieth legions.

Some authors state that very efficient auxiliaries were sent out of Spain also to Marcus Livius by Publius Scipio; namely, eight thousand Spaniards and Gauls, two thousand legionary soldiers, a thousand horse of Numidians and Spaniards together.
That Marcus Lucretius brought these forces in ships, and that Caius Mamilius sent as many as four thousand bowmen and slingers out of Sicily.
39.

A letter which was brought out of Gaul from Lucius Porcius, the praetor, increased the alarm at Rome.

It stated that Hasdrubal had quitted his winter quarters, and was now crossing the Alps; that eight thousand Ligurians had been enlisted and armed, which would join him when he had crossed over into Italy, unless some general were sent into Liguria to engage them with a war.

That he would himself advance as far as he thought it safe with his small forces.