16 mm camera- Mount type?

I'm shooting with a 16mm Bell and Howell 240 camera, and wanted to know if I could rent lenses for it. It's pretty old, but then again theres still a lot of oldy stuff still in use in the film world. Does anybody know what kind of mount it has so I can see if any rental places carry anything that fits it? I tried researching the web and got a lot of tangent information.. which is always fun..