second stages Rhamnacea rank as the 6th and 5th order respectively. In the fourth stage, Proteaceae are not included among the first eight orders, while Compositæ take the fourth place. In the third stage, the remains of but three Conifers are recorded. The proportion of ligneous to herbaceous species is considered to have been very large, there being upwards of 530 of the former, of which number more than one half were arborescent. 327 are reckoned to have been evergreen.* The groups which, either in number of species or individuals, especially gave a character to the Tertiary epoch vegetation, are Coniferae, in "Fl. Tert. Helvetiæ" referred to Palmae Populus Salix Myrica Quercus Ulmus and Planera Ficus Platanus Liquidambar Aceracae Lauraceae Proteaceae Rhamnaceae Leguminosae 9 gen. 23 species. Juglandeae Prof. Heer in a chapter entitled "Comparison of Plants of the Swiss Tertiary Flora with species now existing," enumerates 41 species, exclusive of cellular plants, based upon both leaf and fruit or flower remains (marked * in the following list), and in a second list 30 species resting upon leaf remains only, sufficient, however, to enable him to indicate for each species a living analogue. Although I should probably differ as to the specific counterparts in some cases, there can be but little doubt as to many of the generic identifications. These genera are, Woodwardia, Pteris, *Aspidium, Osmunda, *Juncus, *Arundo, Sparganium, Potamogeton, Smilax, Sabal, *Glyptostrobus, *Taxodium, *Sequoia, Myrica, Carpinus, *Populus, *Salix, *Quercus, *Ulmus, *Planera, *Platanus, *Liquidambar, This is Professor Heer's estimate, and I have not the means of analysing it. Dr. Hooker has directed my attention to the importance of ascertaining satisfactorily the exact proportions generally prevailing between ligneous and herbaceous plants, and the proportion of evergreens in truly tropical floras. I presume all the Lauracea to have been reckoned among evergreens by Professor Heer. He says (Recherches, &c., p. 60) ⚫les Lauriers et les Camphriers gardaient sans interruption leur verdoyante parure."-In the South United States, of the six species of Lauracea which occur there, four are deciduous, and in the Himalaya Dr. Hooker informs me some of the order are commonly bare in winter. To the absolute numbers given by Professor Heer, I think comparatively little value can be attached, though probably the relative proportions in, for example, his table of the sequence of orders, may be sustained. + Recherches sur le Climat, &c. p. 55. N. H. R.-1862. M * *Polygonum, *Salsola, *Laurus, Persea, *Cinnamomum, Embothrium, Dryandra, Ficus, Leptomeria, Diospyros, Acerates, Fraxinus, * Liriodendron, *Acer, Ilex, Zizyphus, Berchemia, *Rhamnus, *Paliurus, Rhus, *Juglans, Pterocarya, *Colutea, *Robinia, *Gleditschia, Caesalpinia, *Cassia. In discussing the character of the Swiss Tertiary Flora,* its general relations to existing Floras are indicated. The methods of comparison employed, Prof. Heer says "incontestably prove that, at the Tertiary period Switzerland was inhabited by types which are now scattered over every part of the world, but of which the majority correspond to American species; Europe ranks only second, Asia third, Africa fourth, and New Holland fifth. In Europe it is the Mediterranean region; in America, the Southern United States; in Asia, Japan, the region of the Caucasus and Asia Minor; in Africa, in proportion to their area, the small islands of the Atlantic, which support the greatest number of analogous species." Speaking of the distribution in the Tertiary, as compared with the present period, of generic types, he selects Juglandese as offering a marked contrast between their present wide, and former restricted area. Prof. Heer limits the present distribution of Pterocarya to the Caucasus, Juglans to Persia and North America, and Engelhardtia to the Sunda Islands. Two species of Pterocarya, however, grow in Japan, three species of Juglans are recorded from the same region, where also another generic type is met with in Platycarya (Fortunæa, Lindl.), and Engelhardtia occurs in the Himalaya. Carya is not held to be generically distinct from Juglans by Messrs. Hooker and Bentham. Viewed in respect of the species which contributed most largely to the mass and physiognomy of the tertiary vegetation, he says, "The Flora of Japan with its abundance of Camphor-trees and its Glyptostrobi, that of the Atlantic islands with its Laurels, the American Flora with its numerous evergreen Oaks, Maples, Poplars, Plane-trees, Liquidambar, Robinia, Sequoia, Taxodium, and ternate-leaved Pines, and finally that of Asia Minor with its Planera and Populus mutalilis occupy the first place." Without distinction of stage in the Swiss deposits, the first rank, in respect to abundance of individuals, Prof. Heer assigns to Lauraceae, second, Cupuliferae. In the first stage, Proteaceae, Rhamnaceae and Cupressineae predominated; in the second, Rhamnaceae and Palmaceae; third Proteaceae; fourth, Salicaceae, Aceraceae, Papilionaceae, Juglandeae and Sapindaceae. The climate of Europe he believes to have been, during the lower miocene, about 13°, and the upper miocene 16° Fahr. warmer than at present, while the large relative proportion of ligneous, evergreen and aquatic species, with layers of lignite, bear testimony to its ample humidity. With a view to avoid unnecessary repetition in the following paragraphs, and to save space, I have drawn up the subjoined table, showing the distribution of existing genera of the Swiss Tertiary in the recent Floras of Europe, Japan, of Europe and Asia (including Japan), taken together, and the Southern States of America. * Recherches sur le Climat, &c. p. 58. The Tertiary and existing Flora of Europe.-The genera common to the Tertiary Flora of Switzerland, and the recent Flora of Europe, as shown in the above table, are about 76 in number; (Dicots. 60; Monocots. 16) or 12 fewer than are common to the Tertiary beds and the South United States Flora, and but 1 fewer than are common to the same and Japan. Of the characteristic orders and groups of the Swiss Tertiary the constituents in the existing Flora of Europe are Gen. Species. Gen. Species. Palmæ +Lauracea The nine largest orders of the Swiss Tertiary are marked † in the above list. According to Professor Heer,* the recent Flora of Switzerland includes 24 natural orders with ligneous species,† of which 18 are common to the Tertiary beds. These latter are-Coniferæ, Amentacea, Ulmacea, Elaeagnea, Aristolochiacea, Thymeleæ, Apocyneæ, Oleaceæ, Ericaceae, Caprifoliaceæ, Araliacea, Cornacea, Tiliacea, Ilicineæ, Rhamnacea, Celastraceae, Acerineæ, Berberideæ. These orders include in the recent Flora 152 species, in the Tertiary 253. In Britain there are about 1230 Phanerogamia (Dicots. 923, Monocots. 307) referred to 479 genera (Dicots. 365, Monocots. 114), and 88 natural orders (Dicots. 73, Monocots. 15). About 116 species (9 per cent.) are ligneous. Of British genera about 48 are common to the Swiss Tertiary (Dicots. 37, Monocots. 11). The Bovey Tracey fossil remains Professor Heer has shown to be pre-eminently characterized by Miocene species.§ Out of 49 species which have been discovered, 20 occur in Miocene beds on the Continent. The Bovey Flora includes the following recent genera : Phragmites | Laurus Sequoia Ficus Quercus Eucalyptus? Eugenia Celastrus Nyssa || Pterocarya? Vaccinium Andromeda Gardenia Professor Heer points out that none of the Bovey species are common to the Miocene of Iceland, and that, excepting Sequoia and Quercus, the genera are also distinct. In Iceland there are, according to Dr. Lindsay's list (1860), 426 Phanerogams (Dicots. 290, Monocots. 136) belonging to 159 genera (Dicots. 119, Monocots. 40), and about 48 natural orders (Dicots. 39-40, Monocots. 8). The only woody plants are birch, willow, juniper, and rose. Common to the Swiss Tertiary there are in Iceland The following genera occur in Tertiary beds in Iceland :-Sparganium, Pinus, Sequoia, Betula, Alnus, Salix (rare), Corylus, Quercus, Ulmus, Platanus, Acer (A. otopterix, being the commonest Tertiary tree), Vitis, Liriodendron, Rhamnus, Rhus, Juglans. The Tertiary and Japanese Floras, &c.-About 71 natural orders are common to Japan and the Swiss Tertiary; of these 51 are represented by identical genera, accepting the determinations of "Flora 1. c. p. 38. † Exclusive of Leguminosa, Rosacea, Ranunculaceæ. I have united some of Prof. Heer's Orders for the sake of uniformity. § Paper read before Royal Society, Nov. 21, 1861. || Very doubtful, especially the last two. |