Calendars not showing up on iPhone

I have 3 "On My Mac" Calendars on my iPhone and one Calendar that is listed under my Google account name so that it syncs with my workplace's google calendar. Everything works great on my computer, and events add in any calendar show up on my iPhone.

The problem is, when I add a new event to my iPhone iCal, only the three "On My Mac" calendars show up, and not the one linked to the google account. This really does me no good! It means I have to add to a different calendar, sync to my computer, then switch the event from one calendar to another before it will sync with google. I add so many events everyday, I'd go crazy trying to move all of them.

How do I get ALL of my Calendars to show up in my iPhone so that I can add events in that calendar?

thanks