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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 vegetaux fossiles, says of Spheno- 
phyilum that “ great attention is necessary in order to avoid 
confounding it with certain species of Asterophyllites;” and 
again he says of the fructification of Sphenophyllum that it 
“ is too analagous to that of Asterophyllites to allow of any 
doubt as to the affinities of these two genera 5 (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 Royal 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 Williamsons remarks his opinion expressed at the 
meeting of the Society on the 4th day of March last was 
not altered. Sphenophyllum 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 jenemetrompe ces tiges curieuses 
appartiennent a des sphenophyllum, du moins c’est ce que jai 
<icrit dans les comptes rendus de bacademie en 1870.” And 
again “ Je n’ai pas encore rencontre de feuilles adherentes 
au rameau ce qui m’a empeche de determiner specifique- 
