HP Pavilion g4 dvd drive won't mount

I installed Ubuntu 16.04 LTS on my HP Pavilion g4 laptop. It’s a great OS, but the dvd drive will not mount and I don’t know why. Do I need to install a linux driver or are there any mounting instructions that I don’t know about.

Is automount enabled in caja ? Do you see the dvd drive in computer:// ( You can go there by accesing the monitor icon (computer) on desktop or enter computer:// in caja location bar . )