220 Successive Geological Development, 



tains in the moUusca. Thus, the Calamites arenaceus is said 

 to afford an example of a plant common to the coal-measm^es 

 and the trias ; but this, I believe, is incorrect, for this species, 

 Mr Morris tells me, was admitted into Mr Prestwich's list of 

 fossils from the coal-measures of Coalbrook Dale by mistake ; 

 and even were it true that the range of this and several other 

 species was occasionally so great as to extend from the coal 

 to the trias, or from the trias to the oolite, such cases would 

 aflPord ntf parallel to the pretended occurrence in the Alps of 

 a large assemblage of plants proper to the coal in the midst 

 of a Jurassic fauna. 



Some years after the publication in 1828 of M. Brongniarfs 

 first list of plants from the Alpine anthracite, that botanist 

 had an opportunity of studying a still larger number of species 

 from the same formation, so as to raise the number to forty, 

 yet they all of them were still found to belong to the old car- 

 boniferous type, without the slightest intermixture of any 

 newer or Jurassic forms. Still later, when M. Sismonda had 

 satisfied himself, after visiting Petit-Coeur in company with 

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

 Jurassic 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 de- 

 posited 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, pub- 

 lished in the fifth volume of your Journal, shews how entirely 

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

 time, he reviewed the several conjectures which had been 

 thrown out by naturalists to explain away or solve the 

 enigma, and pronounced them to be all equally unsatisfac- 

 tory. 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 disappear, whilst a 



