PRE-CARBONIFEROUS FLORAS. 



449 



in recognising the true nature of the Stcrnhergim ; but when 

 the outer wood has been denuded, it becomes ahnost im- 

 possible to determine to what plant they may have belonged. 

 The genus Cyperites comprises elongated linear leaves, which 

 appear truly to be the leaves of Sigillarim. The genus 

 Asterophyllites (fig. 702) comprises elegant plants with 

 ribbed and jointed stems. The joints of the stems give off 

 verticils of leaves, or branchlets bearing whorls of leaves, 

 which are narrow, elongated, and furnished with a single 

 midrib. According to some authorities, Asterophyllites is 

 really founded upon the foliage of Calamites. The genus 

 is not only found in the Devonian series, but is com- 

 monly represented in the Coal-measures, to which the species 

 here figured belongs. 



The genus Annularia comprises plants which are of doubt- • 

 ful affinities, but which possessed slender stems bearing at 

 intervals whorls of leaves. The Annularim appear to have 

 been floating plants, and they occur in both the Devonian 

 and Carboniferous formations. 



Fig. 702.— Asterophyllites foliosus. Coal-measures. (After Lindley and Hutton.) 



The fossils known as Pinnularim are slender stem-like 

 bodies, with a smooth or striate surface, producing at right 

 angles long slender branchlets. The genus Pinnularia is 

 regarded by Dawson as being founded upon the roots of 

 other plants, such as Asterophyllites or Calavnites. 



Lastly, we find in the Devonian rocks the little fruits 

 known as Cardiocarpon and Trigonocarpon, which are so 



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