Harald Othmar Lenz (1799–1870) was a German naturalist and teacher from Gotha who wrote widely on local zoology and natural history. He is best known for practical, observational works for both specialists and educated lay readers — among them a comprehensive treatment of snakes that circulated under titles such as Schlangenkunde and later Schlangen und Schlangenfeinde. Lenz’s career and authorship are documented in contemporary bibliographies and biographical entries. Here are first editions of Lenz's Schlangenkunde in octavo: 559 pages (cloth) and a very rare set of ten accompanying hand-coloured lithographs. The plates are contained in their original printed wrappers, loose, and held in a specially-made portfolio with ties. The portfolio is 32 x 24 cm. The work with these plates was issued in Gotha in 1832 (often cited as Abbildungen zur Schlangenkunde or the plates that accompany Lenz’s Schlangenkunde), and a later, much revised edition of his snake book appeared in Gotha in 1870 under the title Schlangen und Schlangenfeinde. A very scarce set indeed, especially with text and plates.