Another beautiful cover is this one, found on Pyle's novel The Garden Behind the Moon:
Beginning in 1903 and concluding in 1910, Pyle published a four-part retelling of the Arthurian legends. These books featured numerous striking black and white illustrations. The donation contained multiple copies of these books, including special 1933 editions commemorating Pyle's eightieth birthday. Other notable artists contributed new frontispieces for the novels.
Going through the books has been a very enjoyable experience- it's not every day that I get to handle old books like these.