I suggested Coryphantha for the first one because I can't see any tufts between the tubercles. And because the central spine does not have a hook. It doesn't seem very Mammillaria like to me without those two features. I know not all Mamm's have a hook (but the ones with a central spine like that do seem to have hooks) but they do all have tufts or bristles or... between the tubercles.
I said #2 was a Mamm. assuming it is the one listed separately later. If not, looks like there are tufts down there so Mammillaria.
Daisy
