NOTE. 
ON LYGINODENDRON AND HETERANGIUM. By the 
late W. C. Williamson, LL.D., F.R.S., Emeritus Professor of Botany 
in the Owens College, Manchester, and D. H. Scott, M.A., Ph.D., 
F.R.S., Honorary Keeper of the Jodrell Laboratory, Royal Gardens, 
Kew \ 
Introduction. 
The two genera, Lyginodendron and Heterangium , are among the 
most interesting and at the same time the most puzzling representa- 
tives of the carboniferous flora. Although we are still without any 
satisfactory evidence as to the reproductive organs in either genus, 
yet the organization of their vegetative members is preserved with 
such completeness and perfection as to show that these fossils 
present a combination of characters such as exists in no living group 
of plants. 
The evidence afforded by the vegetative characters clearly points to 
a position intermediate between ferns and Cycadeae. 
I. Lyginodendron. 
Lyginodendron oldhamium , Will. 2 , is one of the commonest fossils 
preserved in the calcareous nodules of the Lancashire and Yorkshire 
coal-measures, and has also been found in those of Germany and 
Austria. A renewed investigation, with the aid of numerous addi- 
tional specimens, has enabled us to clear up many doubtful points in 
1 Abstract of a paper read before the Royal Society on June 13, 1895, forming 
Part III of Further Observations on the Organization of the Fossil Plants of the 
Coal-measures. 
2 See Williamson, Organization of the Fossil Plants of the Coal-measures, 
Part IV, Phil. Trans., 1873; Part VI, Phil. Trans., 1874; Part VII, Phil. 
Trans., 1876 ; Part XIII, Phil. Trans., 1887; Part XVII, Phil. Trans., 1890. 
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