iPad 2 can't load Calibre Content Server

[elisathon]

iPad 2 iOS 8
MacBook Pro Yosemite 10
Calibre 2.15

I installed ios reader plugin, set preferred reader to iBook. I can access Content Server in Firefox on MacBook Pro easily but Safari on iPAd 2 can't load same localhost address, the one shown in Connect/share, Content Server menu.
I tried Marvin - added the Marvin plugin, set the preferred reader to Marvin, and I can transfer books, so the plugin works for that.

What am I missing about opening the Content Server address in Safari on the iPad2? My Firewall file sharing (afp) is set to allow incoming connections from calibre. I access lots of apps from my MBP browser via wifi using the same 8080 port, so why isn't Safari able to connect out to Content Server?
What am I missing?
Thanks -