120 Remarks on the Ancient Flora of' the Earth. 



ceous animals, identically the same with those found in the chalk 

 of France and England. Fui-ther, we found impressions of ex- 

 actly similar leaves of dicotyledonous plants in the chalk-marl 

 near Wernigerode. In the same hand specimen we here observed 

 leaves connected with a well-preserved specimen of Belemnites 

 mucronatus ; and I have since had an opportunity of witnessing 

 the great similarity between these with the impressions of leaves 

 found by Professor Nilson in the greensand of Schonen. In 

 the chalk of Westphalia, which is almost uninterruptedly con- 

 joined with that of the Netherlands and the north of France, 

 and which are noted for characteristic fossil remains of animals, 

 there are frequently found remains of plants undoubtedly be- 

 longing to the land. In the quarries near Soest, Werl, and 

 Unna, we often found in the strata of grass-green sandy marl, so 

 abundant in these places, pieces of a coaly substance, distinctly 

 exhibiting the fibrous texture of wood. Equally numerous in 

 those places are the remains of a plant, which, from the most 

 perfect specimens we could find, undoubtedly belongs to the fa- 

 mily of Lycopodiacece. It shews some slight analogy with the 

 (Lycopodiol. dichotomus, Sternb.) particularly with the specimen 

 delineated in tab. ii., and probably belongs to a species not 

 hitherto described. 



It would be easy to multiply the number of facts here given, 

 by comparing a greater number of geological writings. We 

 believe, however, that we may, with sufficient certainty, con- 

 clude, that the boundaries of the periods of vegetation fixed by 

 M. Brongniart are really by no means distinguished by such 

 precise and complete interruptions as he imagines. 



Although there are probably none of the generally distributed 

 strata formed by deposition, in which remains of a contemporary 

 continuous land vegetation are not to be found, it still appears to 

 be a very important question, as regards the crust of the earth, 

 what relations the continued ap})earance of a single species of 

 plants bears to the different periods of the vegetation of a former 

 age. If, in this enquiry, we follow the numerous analogies pre- 

 sented by the relations of the animal creation of a former age, 

 we shall be quite inclined to think, that the Flora of the differ- 

 ent periods of vegetation must be distinguished from one another 

 by perfectly distinct character? of the forms of the plants. In 



