40 : GEOLOGICAL MEMOIRS. TVfSOH 



Aspidiaria, Presl. '-ji'.oa 



Goeppertiana, Stiehl. Grauwacke at Wemigerode [Stiehler^fiii 



acuminata, Gopp. Altwasser. iwoda 



fattenuata, Gopp. Grauwacke of the Hartz (i2w«er) . .....a 



Paclijplilceus, G'dpp. 



tetragonus, G'dpp. Landeshut and Gl. Falkenberg | ,B4,t|fceli»^^2^ 



Mocker, Lasitz, and Dirschel. -jjy^ iBorl-igtBTT 



Megapliytum, y^r^^■5. ' ::,yilt"^o 



KuManum, G'dpp. Dirscliel and Leobschiitz. ,Ay 



Rothenbergia, Cotta. 



fHollebenii, Cotta. Grauwacke of the Rotbenberg near Saalfeld. 



[The last-named species Dr. Goppert believes, from the disposition 

 of the scars, to belong to the genus Meg aphy turn.'] 



The species here brought forward, although few, about sixty in 

 number, and by no means of plentiful occurrence, yet with few ex- 

 ceptions generally distributed throughout the formation, appear well 

 fitted to be regarded as a peculiar Flora, which we provisionally term 

 the Transition Flora. Unquestionably they deserve a separate mono- 

 graph, which I have set about publishing, separate from my other 

 works, in a supplemental volume to the ^ Nova Acta Acad. C. L. Nat. 

 Curios.' I have had the foregoing paper by me for three years and 

 a half, and delayed its publication until the completion of further 

 researches ; but I now publish it, thinking the subject not to be with- 

 out mterest at the present time. 



Dr. Goppert concludes by stating, that m the forthcoming extended 

 work on the Grauwacke Flora, he intends to include not only an 

 account of the fossil plants of the Silesian grauwacke, but of that of 

 other countries, on which subject he will be glad to receive commu- 

 nications ; that H. V. Stiehler of Wernigerode has communicated 

 some new species from the grauwacke-slate of that place ; and that 

 lately in the grauwacke of the Rhine province, previously regarded 

 as destitute of fossil vegetable remains, he has observed, near Hor- 

 bausen and near Coblentz, a new Alga, Haliserites BechenianuSj 

 Gopp., previously discovered by H. v. Dechen. 



[T. R. J.] 



On the Results of the latest Researches explanatory of Carbonic 

 Acid Exhalations. By G. Bischoff. 



[Leonh. u. Bronn's Jahrb. f. Miner. 1849, p. 725, and Verhandl. der Niederrhein. 

 Gesellsch. zu Bonn, 1849, 23 Feb.] 



Bischoff found that carbonic acid was gradually separated from 

 carbonate of hme by silicic acid with the cooperation of boihng water. 

 This decomposition took place, whether the silicic acid was in a solu- 

 ble or insoluble condition ; for even finely pulverized quartz decom- 

 posed the carbonate of lime, the process, however, in that case being 

 rather slower. Carbonated oxydule of iron (Spatheisenstein) and the 

 carbonate of magnesia behave in like manner ; the latter is decom- 



