Unger, F. — Die fossile Flora von Sotzka.

1851 67 p., 47 beautiful chromolithographed pls, small folio (28.5 x 40 cm), disbound (no covers). Unopened and uncut copy. A few plates with some scattered foxing, last plate with small marginal tear (repaired). Published in: Denkschriften der Kaiserlichen Akademie der Wissenschaften. Rare. Franz Unger (1800-1870) is regarded as the founder of botanic palaeontology.