Who are the schoolchildren in Under Milk Wood?

As the residents of llareggub village begin to wake up, Captain Cat, the old blind sea captain, describes the noises he hears, including the school children getting ready for school. When the school bell goes, he states that he hears their feet on the cobbles and is able to list their names as follows:

Maggie Richards, Ricky Rhys, Tommy Powell, our Sal, little Gerwain, Billy Swansea with the dog's voice, one of Mr Waldo's, nasty Humphrey, Jackie with the sniff. . . . Where's Dicky's Albie? and the boys from Ty-pant? Perhaps they got the rash again.

When morning school finishes, the children play a game called Gwennie that consists of the girls singing a song that asks the boys to either give them a penny or kiss them. None of the girls names are mentioned, but the boys that play are Billy, Dicky, and Johnny Christo.
Thomas doesn't go into much detail about the children's characters. Captain Cat only mentions that Billy has a voice like a dog and because of that thinks he is probably the child that hits Maggie. As he says, "Never trust a boy who barks."