First edition of a dissertation on Muraena, a genus of large eels, and Ophichthus, a genus of snake eels, written by Jonas Niclas Ahl (1765-1817) with the prolific Swedish naturalist Carl Peter Thunberg (1743-1828) as "praeses" (advisor). It contains detailed descriptions of 5 species of Muraena and 6 species of Ophichthus, with some general notes on the genera. Most of the species described are found in the Mediterranean or India. Although the imprint includes no date, the dissertation was defended on 27 June 1789.
Plates a bit browned and a small corner torn off page 7/8, not approaching the text. One bifolium has come loose due to the removal of the sewing when the book was disbound. Good copy. BMC NH, p. 20; Cat. Linnean Soc., p. 761; Dean I, p. 14; not in Krok.