300 Count Gaston de Saporta on the Part played 



in calm waters, very feebly charged with a few particles of vei-y 

 fine mud. The vegetable impressions observed in these beds 

 are due to organs which have either fallen in naturally, or been 

 carried by the wind, or, lastly, transported into the lake by a 

 very weak current of very clear water. 



Other beds, on the contrary, are composed of deposits or strata 

 of some thickness, either purely calcareous or composed of a 

 whitish marly limestone, the body of which denotes an abundant 

 mud, arising from the freshets which at certain periods exerted 

 their action with more or less force upon certain points of the 

 lake. They present vegetable impressions belonging to species 

 which, in many cases, may have been carried for a considerable 

 distance, or have arrived from other parts of the country, or at 

 least have been entombed under different circumstances from the 

 former. 



It is therefore probable that the flora of the schistose beds is 

 composed chiefly of the species living nearest to the ancient 

 shore, or within a certain distance of it, and that it contains but 

 few species brought from a distance, except perhaps seeds or 

 light fruits. The flora of the marly beds, on the contrary, pre- 

 sents at once the littoral species and those brought by the muddy 

 waters even from the interior of the country. 



It may also be observed that the forest-trees of the genera 

 Quercus and Cinnamomum and most of the Anacardiace<2 occur 

 in those beds which also contain numerous Andromedce. The 

 leaf of Ulmus plurinervia, Ung., has likewise been met with in a 

 marly bed. 



The schistose beds contain rather the remains of the littoral 

 plants, or of those which inhabited the neighbouring slopes and 

 served as a cincture to the ancient lacustrine sheet on the eastern 

 side. These are Palms, Graminea, Conifera, Myricacea, Pro- 

 teacea, and a few Laurinece, and, lastly, some Rhamnece and 

 Leguminos(B. The most abundant species are common to both 

 sorts of beds. 



It is also in the schistose limestones, or in the laminated 

 marly limestones, that all the scattered fragments of fruits or 

 leaves belonging to deciduous plants of European physiognomy 

 have been met with, with the exception of Ulmus plurinervia and 

 of a strobile of Alnus antiquorum (the leaves of the latter species 

 were probably persistent). It is therefore probable that most 

 of these plants (that is to say, the genera Betula, Populus, Ribes, 

 Acer, Paliurus, and Cratcegus), without inhabiting the margin of 

 the water, occurred in a station within easy access of the ancient 

 shore, and that they were associated rather with the Coniferce, 

 Proteacece, and Leguminosce, than with the Quercus, Andromedce, 

 Cinnamoma, and Anacardiacece, which occur more frequently in 



