Neuchatel, Henri Wolfrath (for the Société helvétique des Sciences naturelles), 1845. Large 4to (32.4 x 25.0 cm). 64 pp.; 15 lithographed plates (numbered 1-14, A). Later quarter cloth over plain blue boards. Spine with paper label with printed title. Original printed wrappers bound in.

An important paper on bivalve systematics, with fine illustrations of new and poorly known species, by the Swiss-American zoologist Jean Louis Rodolphe "Louis" Agassiz (1807-1873). Published in the Society's Nouveaux Mémoires, Volume VII, before Agassiz left for America. Offprint with new pagination. Pictorial, allegorical bookplate of the Academiae Harvardianae Sigillum, "From the Donation Fund of MDCCCXLII" on the front pastedown, and in the top margin of the front free endpaper and title page the stamp of the American malacologist Richard Irwin Johnson (1925-2020). Uncut. Spine top a bit abraded; otherwise very good, clean, no foxing or toning. A very good copy indeed. Caprotti II 6 [170]; Nissen ZBI, 40.