(London, Richard Taylor and William Francis, 1853) 4to. No wrappers as extracted from "Philosophical Transactions" 1853, Vol. 143 - Part I. Pp. 291-310 and 4 lithographed plates. A dampstain to lower right corners of plates.
First appearance of this importent paper, in which Owen established a new genus, Nesodons on the basis of the fossils found by B.J. Sulivan in the Tertiary beds of Patagonia in 1845.