1921.] The Eighth Indian Science Congress. elxiii 
cently classed as Rhaetic (Cotter 1917), there is only one species, 
Cladophlebis denticulata, that occurs in the Jurassic rocks. On 
the contrary, there are at least three important genera, Cor- 
daites, Glossopteris, and Schizoneura, which not only do not 
occur in India above the Rhaetic, but are represented in the 
Parsora beds by species that can be traced as far back as the 
Talchir and Karharbari beds, of Carboniferous age. ! 
There remain only two species, namely, Thinnfeldia odonto- 
pteroides and Danaeopsis (? Thinnfeldia) Hughest, and these 
are generally reckoned as characteristic of Triassic and Rhaetic 
rocks. 
The main point is this: whereas in Europe and elsewhere 
the revolution from an essentially palaeozoic to an essentially 
mesozoic vegetation occurred during the course of the Triasso- 
Rhaetic period, thus dividing the flora of that period into two 
distinct facies, in India this change did not come about till the 
end of the Rhaetic age. The entire Triasso-Rhaetic flora of 
oy) Oo 3 
(Walkom 1918, p. 66; Sahni 1920, p. 21). And it is worthy of 
note that as many as seven of them are Ginkgoales (species of 
Ginkgo and Bavera), while Cordattes and Glossopleris are con- 
spicuous by their absence. 
While this paucity of data regarding the Parsora flora 
VI. Jurassic. 
As soon as we enter the Upper Gondwana period we are 
transported into a vegetation strikingly different from that of 
the Lower. The Cordaitales have gone for ever. So also the 
Glossopterids, along with a host of other fern-like plants, the 
majority of which are under suspicion as being Pteridosperms. 
! Among these species I have neither included Vertebraria indica 
which is known to belong to Glossopteris. nor Samaropsts and the Squamae 
for these may prove to be portions of Cordaites and Glossopteris. 
