332 PALEONTOLOGY. 



These specimens are from Mesozoic rocks, associated with shells of 

 Cretaceous or Jurassic genera. Coniferous woods are most abundant, 

 and belong to Cwpressoxylon and Taxoxylon. Besides these there are 

 two species of Quercus, one of Betula, and one of Fopulus, The fruit 

 and foliage of a Cycad is described under the name Cycadeocarjpus 

 (J)ioonites) Golumhianus. 



De Candolle, a. Constitution dans le regne vegetal de groupes 

 physiologiques applicables a la geographic botanique ancienne et 

 moderne. [Arrangement of the vegetable kingdom in physio- 

 logical groups applicable to the botanical geography of fossil and 

 recent plants.] Arch. Sci. Phys. et Nat. pp. 38. 

 Proposes to group plants in respect of their relation to the external 

 conditions of heat and moisture. Establishes six groups : — 1. Mega- 

 therms^ plants requiring great heat and moisture, such as live at present 

 in the tropics in a temperature over 30° Cent. Representative Orders 

 Anonacece, Guttiferce, Dipterocarpece, Begoniacece, Piperacece, &c. The 

 fossil Megatherms were at first distributed over the globe, but in 

 Tertiary times they were gradually receding towards the Equator. 2. 

 Xerophils, plants requiring as much heat as the first group, but less 

 moisture, such as now live in the hot and dry districts from California 

 and Texas to Mexico, from Senegal to Arabia and the Indus, nearly all 

 Australia, the Cape of Good Hope, and the dry regions of La Plata, 

 Chili, Peru, and the Andes. Eepresentative Orders Zygophyllacece, 

 Gactacece^ Ficoidece, Gycadece, and Proteacece. The fossils are but im- 

 perfectly known. 3. Mesotherms, plants requiring a moderate heat, 

 from 15° to 20° Cent, of mean annual heat, with a moderate amount of 

 humidity. Characteristic Orders Laurinece, Juglandece, Ebenacece, Mag- 

 noliacece, Acerinece, &c. The plants of the Mediterranean basin, of the 

 central plain of Asia, the plains of Chili, &c. The early Tertiary floras 

 represent plants of this group. 4. Microtherms, plants of temperate 

 climes, with a mean annual heat of 0° to 10° Cent., such as form the 

 flora of Europe. The plants are chiefly herbaceous perennials, and 

 deciduous trees and conifers. 5. Hekistotherms, plants which require 

 scarcely any heat, such as those which are found in Arctic and Alpine 

 regions, and are able to endure a long winter. Eepresentative Orders 

 Musci, Lichenes, Graminew, Juncece, GyperacecB, Gruciferce, Saxifragacece^ 

 &c. 6. Megistotherms, plants requiring extreme heat, over 30° Cent., 

 represented now by the Algae of thermal springs, and to which the 

 Algce, Filices, Lycopodiacece, and 'Equisetacece of the Carboniferous period 

 belong. The author considers these groups very stable, passing down 

 through the earth's history with little change, while the forms of the 

 plants themselves and the cHmate have changed ; and he believes that if 

 they are employed they will render the facts of botanical geography, 

 affecting fossil as well as recent plants, more precise and more easily 

 grouped on the basis of general laws. W. C. 



Erdmann, Edw. Fossila ormbunkar funna i Skanes stenkolsforande 

 formation. [Fossil ferns in the coal-bearing formation of Skania.] 



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