What you are looking for is gio mount (it recently replaced gvfs-mount, which replaced gnome-mount).
There is a man page here or you can just type gio help mount for the details
The basic usage is:
gio mount --list --detail to get a list of mounted and mountable volumes
gio mount [-u] <volume> to [un]mount it, e.g. gio mount smb://server/share or gio mount WINDOWS.
Sadly, there seems to be a bug that results in a “Error mounting location: volume doesn’t implement mount” message trying to mount by volume name, but gvfs-mount -d /dev/<devicename> might work.