PHANEROGAMS. 



529 



Transitional Types. — The families Nceggerathiecz and Corda- 

 itea, of the Palaeozoic, appear to include types which are in many 

 respects transitional between the existing Cycads and Conifers, and 

 may therefore provisionally occupy an intermediate position. Both 

 families are, indeed, referred by Mr Kidston to the Cycads, but 

 other writers would place some or all of these forms with the 

 Conifers. In the first family the type genus Nozggerathia, which 

 occurs in the European and North American Carboniferous, 

 has the leaves arranged in two opposite rows (distichous), these 



Fig. 1398. — Leaves of Psygmophylhcm expa?iswn ; from the Permian of Russia. 



leaves having a cuneiform base, with radiating veins which do 

 not form forks. Psygmophyllum (fig. 1398), or Gi?igkophyI!um, 

 is an apparently allied type from the European Carboniferous 

 and Permian, which is placed by Dr Schenk with the Taxoid 

 Conifers. A branch from the upper Devonian of Wyoming, 

 described by Sir J. W. Dawson as Dirty ocordaites is stated to 

 connect Noeggerathia with the under-mentioned genus Cordaites ; 

 since, in place of the parallel venation of the latter, the veins 

 fork at an acute angle, and are slightly netted by the spreading 

 branches of one vein uniting with those of an adjacent one. The 



