Leipzig, Engelmann, 1865-1872. Two parts in two. Folio (35.4 x 25.7 cm [board size: 36.1 x 26.8 cm). Two title pages (as part of a series, and as a stand-alone), 213 pp.; 46 [24; 22] chromolithographed plates, tinted lithographed map, three tables, including two large, folded; printed errata slip. Original quarter cloth over printed boards. Spines with gilt title.

Rare, classic monograph on the Mollusca of the south-eastern part of the North Sea, Germany, by the German marine biologists and malacologists Heinrich Adolph Meyer (1822-1889) and Karl August Möbius (or Moebius; 1825-1908). The latter is also known as an entomologist. Very beautifully illustrated after drawings by both authors and printed at the Lithographical Press in Hamburg. This is one of the few works with numerous fine illustrations of living molluscs, including nudibranchs. It contains the classes mentioned in the titles, and a species of Chiton (Polyplacophora). The first volume with a handwritten dedication by Möbius on the front free endpaper recto, dated 21 November 1872; the second part with, in the same place, a handwritten dedication in another hand – thus probably Meyer's – to J. B. Meyer (a relative?). Provenance: a stamp of the American malacologist Richard Irwin Johnson (1925-2020) in both second titles’ top margins. Nissen, as well as the title pages, quotes a wrong number of plates. Scattered spotting throughout, as usual. A few plates, and several text leaves toned, with some offsetting. Otherwise a very good, complete set. Caprotti II, p. 40 (404); Nissen ZBI, 2805.