Wanted to talk with CD about the astonishing new Pliocene fossil discoveries in North America reported by Leidy. One horse fossil’s dentition, if it could be believed, would be of great interest to CD’s views.

Encloses MS ["On the American fossil elephant", Nat. Hist. Rev. (1863): 43–114]. Shows persistence of specific characters through glacial period.

Eocene monkeys mistakenly described as pigs.

Inquires whether previous letter was received by CD.

Although their views differ, HF is glad they can discuss those differences without offending.

Sends paper on affinities of Plagiaulax ["On Plagiaulax from the Purbeck beds", Q. J. Geol. Soc. Lond. 18 (1862): 348–69].