620 DAVID WHITE 
The regional refrigeration which drove back or exterminated the 
Northern Permo-Carboniferous flora undoubtedly constituted the 
principal environmental cause in the development of the GANGAMOP- 
TERIS flora. In the Greta series of New South Wales this flora 
appears to have been interglacial. The absence of cosmopolitan 
northern types, particularly of the Lycopods, from the beds imme- 
diately following the glacial conglomerates in Brazil, as well as in 
other areas of the pure GANGAMOPTERIS flora can have been due only 
to the inhospitability of the environment to those types at this time. 
Beginning oj return oj northern types.—Although subsequent col- 
lections may show a lower range for some of the types, it would 
appear from the data at present available that in the Brazilian basins 
the first traces of Northern Permo-Carboniferous elements are met 
at 120 meters above the granite where we find Lepidophytic megas- 
pores. At 135 meters above the granite—i. e., in the Nova Estrada 
formation—the same form of spores is mingled with cortical frag- 
ments and leaves of Sigillaria. With them are Equisetites calami- 
tinoides, Schizoneura (?) sp., Sigillaria australis, Sphenopteris 
hastata (?), Glossopteris indica, Glossopteris ampla, Glosso pteris occi- 
dentalis, Noeggerathiopsis Hislopi, and Cardiocarpon Oliveiranum. 
The flora as a whole is still overwhelmingly Southern, most of the 
species being characteristic of the older Gondwana series. 
Continued climatic amelioration.—From a group of coals situated 
about 157 meters above the granite floor, and about 100 meters below 
the top of the Iraty black shale, which forms the base of the Passa 
Dois series, were collected Lepidophloios laricinus, Glossopteris 
Browniana, Glossopteris indica, Glossopteris sp., Vertebraria (?) sp., 
Gangamopteris obovaia, N oeggerathiopsis Hislopi, Cardiocar pon 
Moreiranum and Cardiocarpon Barcellosi, while a carbonaceous 
stratum a little higher is largely composed of the remains of Lepi- 
dodendron Pedroanum, Lepido phloios laricinus and Sigillaria Brardit. 
The collections from these horizons are quite small and insufficient in 
species; but they are ample enough to show conclusively the presence 
of Lepidophytic elements typical of the Northern Permo-Carbonifer- 
ous flora mingling with the GANGAMOPTERIS flora. It is interesting 
to note that at the level of the last-mentioned coal the Lycopods 
again establish their pre-eminent part as great coal-makers. 
