Letter, from George Robert Waterhouse to Sir John Herschel, dated at British Museum Autograph letter signed by sender. Reptile genera in John Frederick William Herschel's [Physical Geography ] are consistent with those of [Edward] Forbes cited in Johnston's Physical Atlas [1854], but new genera have been discovered. Questions John Frederick William Herschel's claim that Elgin sandstone is Devonian. Notes Richard Owen's estimates on pterodactyl size, and distinct tail feathers [illustration] on recent specimen from Bavaria. Corrects John Frederick William Herschel's names for beaver genera. 30 March 1869