Translation of an extract of a letter, from James Theodorus Klein to Hans Sloane, dated at Danzig (Gdansk) States that he will send his small work about the history of fish (stones in their skulls, the hearing of fish and observations of dissected male and female porpoises) when the engravings have been completed by Clifford of Amsterdam; recommends de Superville, privy counsellor to the Margrave of Brandenburg-Bayreuth, to the Royal Society Original letter was in Latin and dated 21 October 1739 Extract from a letter of de Superville to Klein to attached stating that he would like to be elected to the Fellowship Original letter was in French and dated 3 October 1739 1739