Unger has so well described the numerous impressions in his _Chloris Protogæa_, and which have almost become the type of the Miocene flora. "With the exception of the Lignite formations of the neighbourhood of Cassel and Frankfort--the species of which have often numerous points of connection with those of OEningen and Parschlug, and which enter rather into the Pliocene flora--the different localities I have mentioned have numerous relations between them as to their fossil vegetables. Thus, the Nymphea Arethusæ is found in the _Meulières_ or Buhrstone of Paris, and in the marls of Armissan; the Flabellaria rhapifolia and maxima recur at Hoering in the Tyrol, at Radoboj in Croatia, and in the superior sandstones of the environs of Angers and Perigneux. "The Callitrites Brongniartii, Endl., is likewise met with in the formations of Armissan, Aix, in Provence, at Hoering and Radoboj. "Lastly, the Steinhauera globosa of the Altsattel Lignites in Bohemia, is likewise found in the sandstone of the vicinity of Maus; and the Platanus Hercules of Radoboj, in Croatia, has been sent to me from Armissan, near Narbonne, by M. Toumal. "These facts would probably multiply by a more attentive study of the different localities; but as it is, they leave little doubt as to the synchronism of the greater part of these local formations." In the Flora of the Miocene formations, Amphigenous cryptogams occur, represented by Algæ and mushrooms; Acrogenous cryptogams, represented by mosses, ferns, and Characeæ; Monocotyledons, among which we find Naiades, Gramineæ, Liliaceæ, and Palms; of the Gymnospermous dicotyledons, Coniferæ; and Angiospermous dicotyledons, among which occur Myriceæ, Betulineæ, Cupuliferæ, Ulmaceæ, Moreæ, Plataneæ, Salicineæ, Lawrineæ, Umbelliferæ, Karolangeæ, Combretaceæ, Calycantheæ, Leguminosæ, Anacardiæ, Xanthoxyleæ, Juglandeæ, Rhamneæ, Acerineæ, Nympheaceæ, Apocyneæ, and Rubiaceæ. "The most striking characters of this epoch consist of the mixture of exotic forms at present peculiar to regions warmer than Europe, with vegetables growing generally in temperate countries; such as the palms, a species of bamboo, Lawrineæ, Combretaceæ, Leguminosæ of warm countries, Apocyneæ, analogous, according to M. Unger, to the genera of equatorial regions, a Rubiaceæ altogether tropical, united with _erables_, walnuts, birches, elms, oaks, _charmes_, &c., genera proper to temperate or cold regions. The presence of equatorial forms, and particularly of palms, appears to distinguish this epoch essentially from the following one. Lastly, we likewise observe the very small number of vegetables with a monopetalous corolla, limited to species referred to the family of Apocyneæ by Unger, and to the genus Steinhauera, founded on a fruit which has much relation to that of Nauclea among the Rubiaceæ.