Paphiopedilum Arthur is a primary hybrid of (venustum x philippinense). This is an oddball combination to say the least! It was registered back in 1890 and has very beautiful foliage. That’s really all we know about it.
There are a few flower photos that can be turned up with a web search, but I have never seen one in person. It looks like the venustum ‘brain pouch’ comes through to some extent, which is always appealing.