Cannot get xsane to detect my Lexmark CX310dn mfp Scanner on Ubuntu 17.04

I have a Lexmark CX310dn mfp scanner attached over a network. Printing works fine, and I can connect to the printer using http.

I am running xsane 0.999 and I have checked the net.conf file, and saned.conf file to ensure they include the ip address of the printer/ scanner.

If I run sane-find-scanner, it doesn’t seem to check network scanners, and so tells me it isn’t attached as a SCSI or USB scanner.

Running scanimage -L gives the same result.

If I run the GUI xsane, it ponders, then tells me no scanners can be found, and all I can do is exit.

Any ideas as to how to get it to work would be appreciated. With no apparent debug, I am struggling!

Many thanks,