If your are only seeing a very hideous black cursor, with a very circa `95 look, It usually indicates that the only cursor found was Xorg's defaults.
On the other hand, you can get the really solid DMZ cursor theme. The package is named
dmz-cursor-theme, and it had become a fairly common standard cursor these days. Try installing it from the CLI, with this command.
sudo apt-get install dmz-cursor-theme
You might need to restart Xorg to see the cursor reloaded. I'm not sure if this is the cursor you were talking about, but it's been the standard Ubuntu cursor for ages.
Remember that Gnome has cursor tools of its own, but to get that cursor as soon as Xorg has initialized is a different procedure. I believe the whole thing should be set up for you in that package. Personally I hate having the cursor show up from the DM, and then change to another set in the DE. So I always just find a cool one, and set it up as the Xorg default.