7 
Ordinary Meeting, October 19th, 1869. 
J. P. Joule, LL.D., F.R.S., &c.. President, in the Chair. 
“ On a new form of Calamitean Strobilus,” by Professor 
W. C. Williamson, F.R.S. 
The author referred to the labours of Mr. Binney and Mr. 
Carruthers in elucidating the structure of the ordinary type 
of Calamitean Strobili as affording a standard of comparison, 
and then proceeded to describe his specimen, which was 
from the cabinet of Mr. J. Butterworth of High Crompton. 
It had been a strobilus approaching nearer to Aphyllostachys 
than to Volkmannia, only the three lowermost verticils or 
joints were preserved. Externally the central axis had 
been fluted longitudinally like the stems of Calamites. It 
consisted of a medullary cavity surrounded by a cylinder 
consisting largely of cellular and prosenchymatous tissues, 
but also containing, in the prominent external ridges, bundles 
of reticulated vessels. Where these vessels crossed the 
nodes they described a series of arches of which the con- 
cavities were directed towards the medulla, as the author 
had, in a previous memoir, pointed out to be the case 
in Calamopitus. Immediately above and below each node 
the ten external ridges of the axis gradually became more 
prominent until, at the node, they coalesced, converting 
the external grooves of the axis into short canals, of 
which the transverse section was pyriform, and forming 
a continuous foliar disk, chiefly of cellular tissue, in 
which were an outer series of twenty smaller pyriform 
apertures diverging obliquely in pairs from each of the 
ten larger ones. At the outer angle of each smaller 
aperture a sporangiophore ascended almost vertically into 
the cavity of the strobilus, being nearly parallel with the 
central axis. This sporangiophore supported three or four 
sporangia grouped around it in a horizontal verticil, the 
Pkoceedings— Lit. & Phil. Society,— Yol, IX.— No. 2 —Session 1869-70. 
