Tarzan and the Jewels of Opar, by ERB

Tarzan and the Jewels of Opar, by Edgar Rice Burroughs. Grosset & Dunlap printed a more elaborate original version of this novel in 1918, but this version apparently was printed in the same year or soon after. The outer cover seen below was reused multiple times in various ERB Tarzan novels published by G&D. Contrary to most G&D editions, this printing does not have any illustrations aside from the title page.