Can't connect to Android device

On your Galaxy when you plug it in, a notification should pop up in your notification area saying that USB is connected. If you tap it, it should bring up two options. One is use as mtp device and the other is use it as mass storage. Tap mass storage then tap the new notification that pops up and tap the button that says "mount USB storage". It'll pick it up like a thumb drive (or two thumb drives, depending on if you have a memory card.) From then on when you connect it, just tap "mount USB storage" ... or so it works like that on my stock Galaxy S II. Hope it helps!

this may help(if not please give feedback):

sudo apt-get install mtp-tools mtpfs