The letter has not been found, but it was recorded in the minutes of the meeting of the Palaeontographical Society council on 24 February 1854, from which the text given here has been taken.

According to the introduction to Living Cirripedia (1854), CD had not originally intended to prepare a separate volume on the fossil Balanidae for the Palaeontographical Society series. The reason given was that the ‘number of the British fossil species of the Balanidæ and Verrucidæ in a recognisable state is so small, that I do not know whether it will be considered worth while to publish in the Palæontographical series more detailed illustrations than are given in this volume.’ (p. 1 n.).