W. Dawson — ^ew Erian {Devonian) Plant. 



3 



which have this peculiarity, as also certain modern Cycads of the 

 genus Zamia, which Professor Penhallow has kindly pointed 

 out to me. The present plant would seem to be a form of 

 CordaitecBj tending to NcBggerathia^ which many paleobotan- 

 ists believe to have been a gymnospermous genus allied to 

 Cordaites. The affinities, however, so far as can be judged, 

 are nearer to the latter ; and following the example of Grand 

 Eury in his nomenclature of the genera, I would propose the 

 name Dictyo-cordaitea for the present genus, and the specific 

 name Laxsoi, in honor of its discoverer. 



It is apparent that this specimen combines the fructification 

 of the VordaitecB with leaves akin to those of Nc&ggerathia^ 

 thus connecting two groups of paleozoic plants, both of which 

 are now considered as allied to Cycadem and Taxine(B„ and I 

 entertain the hope that when it is fully studied and brought 

 into comparison with other specimens in my collections, or 

 which have been figured and described by other paleobotanists, 

 it will throw additional light on a great number of Paleozoic 

 Canadian leaves, fruits and stems, now designated as Cordaitea, 

 N (Bggerathia^ Psygmophyllum^ Oingkophyllum^ Siembergia, 

 Zepidoxylon, Saportea, etc. ; and which have been waiting for 

 some specimen thus complete to bring them into harmony 

 with each other. 



I hope to be able to bring the whole of this material, which 

 will necessitatfc some change in the nomenclature of some of 

 my own species, under the notice of geologists at the approach- 

 ing meeting of the American Association. 



1 may add that the oldest true Cordaites known to me is C. 

 Rohhii of the Middle Devonian, which is said to have also been 

 found in the Silurian. C. angustifoha of the Lower Devonian 

 is a somewhat uncertain species. Plants of the genus Nc&gge- 

 rathia are known in the Upper Devonian. 



Explanation of piguue. — Dictyo-cordaites Lacoi^ much re- 

 duced, (a) Venation of leaf, natural size, {b) Fruit enlarged. 



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