Lee,
Well those 'true lemurs' on Madagascar must be a backward group that havn't learned to fly yet.

We had the flying variety on Borneo. They are virtually helpless on the ground. We found one that seemed to be injured and kept it in a wooden cage for a couple of days until it gnawed a hole and escaped. I seem to remember it was larger than the 14-17 inches but the long arms with folds of skin probably made it seem larger.