Essay on new observations concerning fresh water polyps, and its summary in Swedish, probably requested by Linnaeus pater who did not read French. Both authors are unknown.
The French 'Memoire' mentions a Mr de Moll le Cadet, who could be Baron Karl Marie Ehrenbert von Moll (1760–1838). Possibly candidates are German naturalists and entomologists Franz von Paula Schrank (1747-1835) or Johann Christian Daniel von Schreber (1737-1810), a correspondent of Linnaeus and with a closely related handwriting.
The 'Memoire' refers to Trembley, A. 1744. "Mémoires pour servir à l'histoire d'un genre de polypes d'eau douce". Leiden. The author of the 'Memoire' is working with 'Mr de Moll le Cadet' on a paper concerning polyps.
The Swedish abstract, entitled 'Memoire angående de observationer som äro giörde på de Polyper som finnes i sött watten', contains some remarks by Linnaeus pater about different classes of polyps.