What are the names of the nine telepaths including the missing one in the Chrysalids?

There are more than nine telepaths in the book, but these are the main group that the story revolves around:

David

Petra

Michael

Rosalind

Katharine

Sally

Anne

Rachel

Mark

That is nine already, but if you are early in the book and there is a missing one ... that is Walter Brent. This is before they share names with each other, but Uncle Axel finds out the name of a nine year old boy from a nearby village who died due to an accident while felling timber, which fits the time frame of when the other member of their group "stopped." This is also before they find out about Petra, so they are eight between Walter's death and the discovery of Petra.