118 Remarks on the Ancient Flora of the Earth. 



appear in corresponding strata, which leaves no doubt of the 

 identity of this formation with that of the zechstein formation in 

 Germany. (Philos. Mag. et Ann. of Philos. vol. iii. p. 302.) 

 If, after the evidence here adduced, we may be permitted to as- 

 sume that there is no very decided distinction between the first 

 and second of M. Brongniart's periods of the vegetation of a 

 former age, the same may, very probably, be the case with the 

 following periods. According to him, the second and third pe- 

 riods are separated by the formation of shell limestone or muschel- 

 kalk. The circumstance, however, that, in this limestone, in a 

 great part of Germany, there is a particular coal formation, ac- 

 companied by remains of land plants (Lettenkohle of Voigt) 

 cannot be here brought forward, for late observations have 

 proved, that this coal formation belongs to the keuper, not to 

 the shell limestone. Hence, on reference to the division of the 

 second and third periods, we can only infer, that the formation 

 of the shell limestone, or muschelkalk, does not belong to the 

 class of rocks universally distributed, and that it may often 

 happen that we find the strata of ketiper that contain plants, as 

 well as those of the variegated sandstone, to be nothing else 

 than upper and under beds of one and the same formation, in 

 conformable stratification. But, lastly, we must dissent from 

 M. Brongniart's opinion in regard to what he considers the up- 

 per boundary of the third peiiod, that only marine plants arc 

 found in the chalk formation. (Ann. des. Sc. n. 4. p. 217. Hist. 

 des. Veget. Foss. libr. ii. p. 85. note, &c.) 



Indeed it is known, that generally in the formation of true 

 chalk, and in that of chalk-marl and grccnsand {quadcrsand- 

 stein) belonging to it, vegetable remains are seldom found, in 

 comparison with the immense accumulation of petrified animal 

 remains which characterise it. According to the most accurate 

 statements, as many of these plants appear to belong to the 

 land as to the sea. If we next, in reference to the chalk of Eng- 

 land, compare the multitude of observations contained in the 

 transactions of the Geological Society of London, we find, first, 

 observed in the chalk of Cambridge near Cherry Hinton, by W. 

 Hailstone (G. Tr. iii. 250), coniferous fruits and branches with 

 leaves, wliich the author is inclined to reckon in the family of the 

 Coniferce. They had been previously described by Parkinson, 



