To J. G. Forchhammer 20 May 
Down Farnborough Kent
My dear Forchhammer
I ought to have written sooner to have thanked you very sincerely for your letter of the 27th of April: it told me quite fully & most clearly, all that I wanted to know of your Geology.1
Prof. Steenstrup’s specimen which I owe first to your kindness have been of great use & interest to me: I have now described 33 fossil Pedunculated Cirripides, & they are in Mr Sowerby’s hands to make drawings of.—
With my very sincere thanks | Believe me | Yours very truly | Charles Darwin
Thanks JGF for geological information.
Steenstrup’s cirripede specimens have been of great use and interest. CD has now described 33 fossil pedunculated cirripedes.