I could not find this on my usual references. Will it cover 4X5?

And, just out of curiosity, can anyone explain the difference between the Tele Xenar and Tele Arton series of lenses? It seems odd that Schneider would have had two designs for the same function unless there was something significantly different between them. I assume that the Tele Xenar, as in the other Xenars, is sharp in the center and less so at the edges. Perhaps the Arton is sharp across the entire field?

The VM says that the Tele-Xenar is a four element lens and that the 240/5.5 will cover 4x5. All it has in common with the normal Xenar, a tessar type, is the word Xenar.

And the VM says that the Tele-Arton is a newer more complex design and overall better.

Schneider, visit http://www.schneiderkreuznach.com/archiv/archiv.htm , seems to agree with this assessment.