Who was Antonio calling in Chapter 11?

Antonio isn't calling anyone. He is, however, being called by Cico.

Hey Toni-eeeeee. Huloooooo Antonioforous!"

A voice called.

At first I thought I was dreaming. I was fishing, and sitting on a rock; the sun beating on my back had made me sleepy. I had been thinking how Ultima's medicine had cured my uncle and how he was well and could work again. I had been thinking how the medicine of the doctors and of the priest had failed. In my mind I could not understand how the power of God could fail. But it had.

"Toni-eeeeee!" the voice called again.