PALEOBOTANICAL EVIDENCE 513 



associated with red-bed deposition is not well founded. . . . However, in 

 opposition to such a conclusion it must be noted that (a) the flora in the red 

 beds has not been observed to differ very markedly from that in the regions 

 of dark contemporaneous sediments, including coal; (&) the plants, though 

 less varied, are not reduced in size, nor, possibly, in number; (c) coal, usually 

 thin, to be sure, occurs in the midst of the red beds of the Conemaugh both 

 in the eastern and the Rocky Mountain regions of America as well as in 

 Europe, some of the coal being thick; (d) the evidence of seasonal growth 

 ('annual rings') in the Conemaugh woods yet examined is slight, though the 

 rings are a little more distinct than in the Allegheny woods; (e) the great 

 calamitean growth appears unimpeded, though many of the giant species are 

 provided with thick xylem and cortex; (/) the nearest living relatives of the 

 Psaronii — the Marattiacere — are now exclusively tropical." 



From these facts it is evident that the climate of this time was mild, 

 practically free from frost, and still abundantly supplied with moisture 

 as attested by the formation of peat. 



In the upper Stephanian, which corresponds approximately to the 

 Monongahela of the North America section, there was a revival of wide- 

 spread uniformity of climatic conditions as indicated by the thick de- 

 posits of coal in many parts of the world. There is evidence in the 

 plants that there was an absence or nearly complete absence alike of 

 winter cold and at least prolonged seasons of drought. White concludes : 



"On the whole the paleobotanical inferences are that during Monongahela 

 time the climate was mild, probably subtropical, and nearly uniform over the 

 greater part of the earth, as shown by the geographic distribution of the types 

 that were able to extend in relative purity of association to identical species 

 round the world from east to west, and from the latitude of England and 

 Manchuria on the north to southeastern Africa on the south." 



The testimony of the animal life of Carboniferous time as to climatio 

 conditions is in substantial accord with that of the plants. Thus, 

 Schuchert ® says : 



"The world-wide warm-water condition of the late Devonic seas of the 

 Northern Hemisphere was continued into those of the Lower Carbonic. These 

 latter seas were also replete with a varied marine life, among which the 

 corals, crinids, blastids, echinids, bryozoans, brachiopods, and primitive sharks 

 played the important roles. Limestones were abundant and with the corals 

 extended from the United States into Arctic Alaska. Reefs of Syringopora 

 are reported in northern Finland at 67° 55' N. . . . The marine faunas of 

 Upper Carbonic time were fairly uniform in development, and many species 

 had a wide distribution. . . . The very large insects of the Coal Measures 

 tell the same climatic story. They were 'brutal robbers' and scavengers living 

 in a tropical and subtropical climate, or at the very least in a mild climate 



» Charles Schuchert : Smithsonian Inst., Ann. Rept., 1914, p. 294. 



