Heinrich Lefler (7 November 1863, Vienna – 17 March 1919, Vienna) was an Austrian painter, graphic artist and stage designer.
Now, he illustrated a lot of books together with his brother-in-law Joseph Urban ((May 26, 1872, Vienna – July 10, 1933, New York City) Austrian-American architect, illustrator and scenic designer), so I don't know which parts of these illustrations are to be credited to which man.