2 
Manchester Literary and Philosophical Society, in 18G9, 
constituted a connecting link between the two extreme 
modifications represented by Calamites, and the so-called 
Calamodendron. Hence, believing that all these three 
varieties were merely differentiations of the common Equi- 
setaceous type, he wholly rejected the conclusion that Cala- 
modendron was a Gymnospermous plant. 
As to the supposed stamens and pollen-grains of M. 
Renault, he demonstrated that they were merely the spori- 
ferous spikes of the Equisetiform Genus Calamostachys, 
which only differed specifically from the common Carboni- 
ferous Calamostachys Binneana which the author had 
figured in his Memoir X., fig. 13 (Phil. Trans., 1880, Plate 
15), whilst in fig. 17 of the same plate he represented the 
spores in identically the same conditions of form, number, 
and grouping as characterised the supposed Pollen-grains 
of M. Renault. Hence, whilst no proof was forthcoming 
that the fructification actually belonged to Calamodendron, 
should it eventually be found to do so, it would only estab- 
lish more completely than before, the Cryptogamic character 
of that genus. 
Ordinary Meeting, October 19th, 1886. 
Professor W. C. Williamson, LL.D., E.R.S., Vice-President, 
in the Chair. 
“On Volcanic Dust from Tarawera, New Zealand,” by 
Thomas Kay, Esq. 
The eruption of a volcano which has been long quiescent 
is usually attended with the phenomena of mud streams 
with scoria in various forms of division. 
This scoria is often ejected to a very great height. It is 
