This should explain what you have now. (Disassembly and reassembly of the two piece driveshaft from the 1941 Shop Manual)

http://chevy.tocmp.com/1941shop/41csm109.htm


Open driveline uses u joints at both ends of the driveshaft and is not enclosed.

http://en.wikipedia.org/wiki/Hotchkiss_drive

Torque tube definition.

http://en.wikipedia.org/wiki/Torque_tube

More driveline definitions.

http://www.bchra.org/TipsTricks/RearAxleBasics.htm

Hope this helps.

"Nothing astonishes men so much as common sense and plain dealing." - Ralph Waldo Emerson