Hi There Totalspoon,
It was an AEG G.II; very likely G.II G6/15. You need to get a copy of James F. Miller's SUPERB new book on MvR,
Air Power Editions No. 3, Manfred von Richthofen - The Aircraft, Myths and Accomplishments of the Red Baron.
It has a photo of the very G.II G6/15 flown by Zeumer and MvR, marked with Zeumer's 'black cat'; insignia. The same photo, and a color profile, appears in Ed Ferko's marvelous book
Richthofen. Also recommended!!