I wanted to be able to access my USB storage disk attached to my NeatGear WNDR4000 router from Linux Mint 19 Tara. More specifically, add it as a drive in the Nemo File Manager.

After quick internet search turned up the Samba command:

smb://readyshare/USB_Storage

I tried that in the address bar in Nemo but it did not work.

The trick was to use the router's IP address instead of 'readyshare'. In my case, it is the default address for the NetGear router:

smb://192.168.1.1/USB_Storage

Now to add it to the left hand panel in Nemo; select File -> Connect to Server... in the menu to open the dialog box.

DialogDetails

After filling in the details, click the connect button. The first time I did this, Mint filled in the bottom half of the dialog and asked me to confirm my password. After filling in the password and checking the 'Remember this password' box, it has worked fine.