107 



sustain each other in the strongest possible manner. Nearly 

 every writer who has dealt with these subjects has recog- 

 nised Annularia and Sphenophyllum as genera of plants 

 having the closest possible mutual affinity ; they are 

 invariably arranged side by side. Brongniart, in his 

 Tableau des genres de v4getaux fossiles, says of Spheno- 

 phyllum that "great attention is necessary in order to avoid 

 confounding it with certain species of AsterophylKtes;" and 

 again he says of the fructification of Sphenophyllum that it 

 " is too analagous to that of AsterophylKtes to allow of any 

 doubt as to the affinities of these two genera" (loc. cit. p. 52). 

 Mr. Carruthers, in his lecture " On the Cryptogamic Forests 

 of the Coal Period," says of Asterophyllites, Annularia, and 

 Sphenophyllum, " it is possible they may be found to con- 

 stitute three genera, but there are no characters possessed 

 by the leaves which prevent them belonging to one well 

 defined genus." (Proceedings of the Eoyal Institution of 

 Great Britain for April 18th, 1869.) I could easily multiply 

 similar illustrations of my statement, but I have probably 

 said enough to prove that, so far from the " conclusions" of 

 Professor Renault and myself on this point being opposed 

 and " different," we have been independently and unknown 

 to each other arriving at what are practically identical con- 

 clusions respecting the stem under consideration. 



E. W. BiNNEY, F.R.S., said that after having heard Pro- 

 fessor Williamson's remarks his opinion expressed at the 

 meeting of the Society on the 4th day of March last was 

 not altered. Bphenophyllvbin and Asterophyllites have al- 

 ways been considered as distinct genera of plants, and they 

 are so described in Professor Schimper's great work. Pro- 

 fessor Renault writes, " Si je ne me trompe ces tiges curieuses 

 appartiennent a des sphenophyllum, du moins c'est ce que j'ai 

 t^crit dans les comptes rendus de I'academie en 1870." And 

 again " Je n'ai pas encore rencontre de feuilles adherentes 

 au rameau ce qui m'a empeche de determiner specilique- 



