(London, Taylor and Francis, 1859). 4to. No wrappers as extracted from "Philosophical Transactions" 1859 - Vol. 149 - Part I. Pp. 161-169 a. 1 lithographed plate.
First printing. Owen gives a more detailled description of Dimorphodon which he named in the same year as the offered paper. Dimorphodon was a genus of medium-sized pterosaur from the early Jurassic Period. It was named by Owen in 1859 (in a paper preceeding the offered paper).