1876.] Knowledge of the Fossil Flora in India. 339 



pass out from the base as two or more main- veins and spread out in the leaf 

 surface repeatedly bifurcating. 



The stalk, which as I have mentioned, is articulated, is rarely striated 

 on the surf ace ; the internodes are of different lengths. 



As regards the nature of this genus and its relations, it was first 

 described as belonging to the Marsileaceae* by Brongniart ; Lindley and 

 Huttonf considered it to be one of those plants which in the ancient 

 world represented the pine tribe of modern floras. 



Mr. Unger in 1845 % also placed Sphenophyllwm with the Mar sileaceae, 

 while in 1850§ the same author ranged it with the Asteropliylliteac,\\ 

 placing this order, together with the Fquisetaceae and the Calamiteae, in the 

 class Galamarieae ; and from that time until Schimper's ' Palseontologie 

 vegetale' appeared in 1869 we find Sphenophyllum (as a peculiar genus) 

 generally ranged with the Fquisetaceae. 



I think it would be quite unnatural to consider it as belonging to the 

 Marsileaceae, as there in the whole world amongst all the Marsileaceae is not 

 a single form which has more tban one leaf- whorl coming out from the 

 rhizome on a thin stalk, which is never articulated. 



Some years ago, however, Mr. Carruthers^f endeavoured to unite not 

 only Asteropliy Rites, Bgt., with the genus Catamites, Bgt., as leaved branch- 

 es of it, as Mr. Ettingshausen** had already done, but also the genus Sphe- 

 nophyllum, Bgt., although this last is so characteristic. 



But quite recently we have some further investigations about this 

 genus by Mr. Williamsonff and by Prof. Renault. % % 



The latter author would prove that Sphenophyllv/m cannot possibly be 

 an equisetaceous plant, just what Mr. Williamson had attempted to show 

 in the case of Asteropliy Rites ; and both these authors would have us 

 believe that Asteropliyllites and SpJienophyllum are very closely allied genera 

 and more closely allied to lycopods than to any other plants. A com- 

 munication on this subject in the above-mentioned sense I have in a letter 

 of Mr. Williamson (1875). 



* Brongniart, Prodrome, 1828 p. 68. Eoyle, 1. c. p. 431. XXIX. 



t Fossil Flora of Great Britain. Vol. I. 1831-33. pp. 41-44, 86. 



% Synopsis plant, foss. pp. 112-114. 



§ Genera et spec, plant, foss. p. 69 seqq. 

 Including Yolkmania, Huttonia, Asteropliyllites, Annularia, etc. 



IT The cryptogamic forests, Geolog. Magaz, 1868. 



** Haidingers Naturwissenschaftl. Abhandl. 1851. Flora der Steinkohlenfornia- 

 tion von Eadnitz. Abh. d. K. K. Geol. Reichsantst. 1852. 



ff Philosophical Transactions, 1874. p. 41 seqq., Pis. I — IX. 



%X Researches sur 1' organisation des Sphenophyllum et des Annularia, Mem. del 

 Acad, des Science. Paris. 1870. 



