This should work for all Ubuntu linux versions. It’s testet with Linux Mint Mate 17.1 Rebecca.

Install srceensaver packages:

sudo apt-get install xscreensaver-data-extra xscreensaver-gl-extra

Make them usable with Mate:

cd /usr/share/applications/screensavers
sudo perl -p -i -e 's/OnlyShowIn=GNOME;/OnlyShowIn=GNOME;MATE;/g' *.desktop

Now you have a big selection of screensavers in your preferences.

Credits to Sergey Potapov and bladerunner6978.
http://greyblake.com/blog/2013/02/02/install-more-screensavers-on-mate-desktop/