26 



ever, go to show that a plant with Noeggerathoid leaves 

 might have a fructification similar to that of Oordaites. 



It has further become a question with palseobotanists to 

 what extent some of the broad, flabellate and rounded leaves 

 referred to Cyclopteris and other genera of ferns, may belong 

 to gymnospermous plants of the nature of Noeggerathia. 

 Of these leaves those already referred to of the genus Doler- 

 ophyllum seem certainly to be Gymnospermous. The pecu- 

 liar fan-shaped leaves described by Newberry under the 

 name Whittleseya, 1 and of which one species occurs in the 

 coal formation of Nova Scotia, belong apparently to the 

 same category. The singular unilateral leaves, or fronds, 

 of which my Naggerathia dispar from Nova Scotia was the 

 type, and which Fontaine has recently separated in his 

 genus Saportea* may also be gymnospermous. Less cer- 

 tain is the reference by Saporta to this group of the genus 

 Cannophyllites of Brongniart, and of the large and beautiful 

 Erian and Lower Carboniferous fronds of my genus Mega- 

 lopteris. 3 



I have already referred to the numerous Gymnospermous 

 seeds known in the Palaeozoic, and belonging to the genera 

 Trigonocarpum, Cardiocarpum, Rhabdocarpus, etc. 



The structure of many of these has been illustrated by 

 Hooker, C. Brongniart, Williamson and myself, and they are 

 unquestionably allied to the seeds of Oycadece and Taocinece. 

 When the vast abundance of these seeds on certain beds is 

 considered, and the fact that Schimper catalogues 67 species, 

 while recent discoveries would nearly double that number, 

 it becomes evident that plants of this grade must have borne 

 a very important part in the palaeozoic vegetation, and we 

 have reason to suspect that many stems and leaves now of 

 uncertain affinities will be found to have been of this class. 



We may now tabulate as follows the principal Gymnos- 

 permous groups which may be represented in the Palaeo- 

 zoic : 



1 Lesquereux " Coal Flora." 



2 " Permian Flora." 



3 " Evolution du Monde Vegetal. 



