﻿xlvi PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



still found to belong to the old carboniferous type, without the slightest 

 intermixture of any newer or Jurassic forms. Still later, when M. 

 Sismonda had satisfied himself, after visiting Petit-Cceur in company 

 with M. Elie de Beaumont, that the evidence in favour of the Juras- 

 sic age of the fossil plants could not be impugned, he proposed to me 

 to invite some English botanist to examine the fossils of the Alpine 

 anthracite collected by him and deposited in the Museum at Turin, 

 that they might again undergo a rigorous scrutiny. Our Foreign 

 Secretary, Mr. Bunbury, undertook this task in 1848, and his paper, 

 published in the fifth volume of your Journal, shows how entirely he 

 confirmed the conclusions of M. Brongniart. At the same time, he 

 reviewed the several conjectures which had been thrown out by natu- 

 ralists to explain away or solve the enigma, and pronounced them to 

 be all equally unsatisfactory. It had been urged by some writers, 

 for example, that as the same coal plants have a wide range in space, 

 both in latitude and longitude, reaching north and south from Mel- 

 ville Island to Alabama, and east and west from Indiana to Russia, 

 they may have also had a great vertical range or duration in time. 

 To this hypothesis there is this obvious answer: — Even in the Permian 

 strata we perceive most of the carboniferous species beginning to dis- 

 appear, whilst a perfectly new flora appears in the Triassic sera. 

 Again, in the Liassic epoch, we find other distinct vegetable forms, 

 not only in Europe, but in America and India, as will be seen by con- 

 sulting for the United States the memoirs published by Prof. W. B. 

 Rogers and myself on the oolitic coal-field of Virginia, and for the 

 East by the accounts given by Captain Grant of the flora of the Cutch 

 oolite*. If, on the other hand, we reflect on the wide extent, in the 

 present state of the globe, of botanical provinces, each inhabited by 

 its own assemblage of plants, we must regard the Vosges as not far 

 distant from the Tarantaise Alps. Yet in the chain of the Vosges in 

 Alsace we find, even at the period of the Lower Trias or Bunter, a 

 vegetation wholly different from the carboniferous ; and the Keuper 

 again, or Upper Trias, displays according to xldolphe Brongniart an- 

 other flora more approaching to the oolitic. What is still more deci- 

 sive, in the Department of the Isere, at no great distance from the 

 limits of the anthracite formation of the ^Alps, Jurassic strata occur 



* Quart. Journ. Geol. Soc. vol. v. p. 13G. 



