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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



[Mar. 20, 



be rash to conclude that such were general characteristics of the 

 Indian flora in those times. Some might be disposed to account 

 for this monotony by supposing that the fossil plants of Nagpur 

 are merely the scanty remaining fragments of a rich vegetation ; 

 and that the other plants with which they were associated, being less 

 adapted for preservation, have entirely perished ; but it is hardly 

 possible to admit this explanation when we observe the remark- 

 able variety of vegetable forms in the tertiary plant-beds, which 

 must also have been deposited nnder water. We do not know of 

 any conditions which would account for the preservation of so many 

 various forms in the one case, and of so few in the other. 



2. Another and very striking characteristic of this Nagpur fossil 

 flora, is its close analogy with that of the coal-formation of Aus- 

 tralia*. The prevailing plant in each of the deposits is a Glosso- 

 pteris, and it appears (as far as we can judge in the present state of 

 our knowledge) to be actually the very same species in both. My 

 Glossopteris leptoneura, an abundant plant in the Nagpur beds, is 

 very closely allied to the Australian Glossopteris linearis^. Another 

 most abundant plant of the Nagpur deposit is a Phylhtheca, a 

 genus especially characteristic of the Australian coal- formation ; and 

 the species, though not identical, is very similar to those of New 

 South Wales. I may add the genus Vertebraria, which, though I 

 have met with no certain evidence of its occurrence in the Nagpur 

 district, is known to be common to the Bengal and Australian coal- 

 fields j\ Thus it appears that those vegetable forms which are most 

 striking by their peculiarities, and most characteristic by their abun- 

 dance, are common to these two distant countries. At present, as 

 is well known, the vegetation of extra-tropical New South Wales is 

 very widely different from that of continental India. If, indeed, 

 we compare tropical Australia with India, we find, as Dr. Hooker 

 has shown §, a very marked agreement between their floras ; nearly 

 oOO species being common to the two. These indeed are plants of 

 very different character from those which occur as fossils in either 

 country, and afford very different climatic indications ; they are the 

 plants of a dry climate and of open and arid countries ; whereas the 

 fossil plants must, in all probability, have grown in or near extensive 

 swamps or large bodies of water. It is however worth observing 

 that, where the physical conditions of the two countries are nearly 

 similar, there is at present this marked agreement between their 

 floras. It is also to be observed that in each of the fossil floras 

 which we are comparing, the Ferns are the predominant family, and 

 that the Ferns of Australia at the present day are among the least 

 peculiar portions of its vegetation. Several species of this family 

 are common to India and New South Wales ; such are Drynaria 

 irimdes, D. que m folia, Asplenium nidus, Davallia elegans, Cheil- 



* See Morris in Strzelecki's New South Wales ; and McCoy in Ann. Nat. 

 Hist. v. p. 20. 



t And may possibfy not be specifically distinct from it. 



i See McCoy at. *vj)ra. and De Zigno, Flora Foss. Form. Oolith. 



§ Introductory Essay on Flora of Australia, p. 42. 



