366 ASTEROPHYLLITES — SIGILLAEIA. [Ch. XXIV. 



In conclusion, I may remark, that these discoveries make it more and 

 more doubtful to -what family the greater number of Calamites should be 

 referred. Their internal organization, says Prof. "Williamson, was very 

 peculiar; for, while they exhibit remarkable affinities with gymno- 

 spermous dicotyledons, the arrangement of their tissues differs widely from 

 that of all known forms of gymnosperms. 



Aster ophyllites. — The graceful plant represented in the annexed figure, 

 is supposed by M. Brongniart to be a branch of the Calamodendron, 

 and he infers from its pith and medullary rays that it was dicotyledonous. 

 It appears to have been allied, by the nature of its tissue, to the gym- 

 Fig. 4T9. 



Asterophyllitesfoliosa. (Foss. Flo. 25.) Coal-measures, Newcastle. 



nogens, and to Sigillaria. But under the head of Asteropkyllites many 

 vegetable fragments have been grouped which probably belong to differ- 

 ent genera. They have, in short, no character in common, except that 

 of possessing narrow, verticillate, one-ribbed leaves. Dr. Newberry, of 

 Ohio, has discovered in the coal of that countiy fossil stems which in 

 their upper part bear wedge-shaped leaves corresponding to Spheno- 

 phyllum y while below the leaves are stalk-like and capillary, and would 

 have been called Asteropkyllites if found detached. From this he infers 

 that Sphenophyllum was an aquatic plant, the superior and floating 

 leaves of which were broad, and possessed a compound nervation, while 

 the inferior or submersed leaves were linear and one-ribbed. " This 

 supposition," he adds, " is further strengthened by the extreme length 

 and tenuity of the branches of this apparently herbaceous plant, which 

 would seem to have required the support of a denser medium than air."* 

 Sigillaria. — A large portion of the trees of the carboniferous period 

 belonged to this genus, of which about thirty-five species are known. 

 The structure, both internal and external, was very peculiar, and, with 

 reference to existing types, very anomalous. They were formerly refer- 

 red, by M. Ad. Brongniart, to ferns, which they resemble in the scala- 

 riform texture of their vessels, and, in some degree, in the form of the 



* Annals of Science, Cleveland, Ohio, 1853, p. 97. 



