Cone lenses are rod lenses with a conicial point, and are used by shining incident light along the long axis of the lens to create a circular illumination pattern. The diameter of these lenses are often ground to reduce stray light.
Rod lenses are a varient of cylindrical lenses used to focus incident light into a line. The outside faces of the lens are typically ground and the outside diameter polished. These lenses are often used for generating line images from circular laser beams.