"UM blue and white swirls clear center"
The first one here, #42, is a West Virginia swirl. WV swirl for short. Around 10 companies in West Virginia made similar marbles, so we often lump them together under that name. Sometimes we'll try to narrow down the company. It's an inexact science though.
#42 could be from the Ravenswood or Alley company.
I was having trouble getting a vibe from the next two. But now I think the middle one, #18, might be a Peltier.
The last one, #10, is still not speaking to me.