37 
ment is altered. If prolonged, the cellular wedges of one 
joint would run into the fibrous wedges of those above and 
below it. But as the fibres of the fibrous wedges are conti- 
nued from one internode to the other, they break up as they 
approach each node, their fibrous laminae being twisted in 
an extraordinary manner as they cross the node, in order to 
redistribute themselves right and left to the fibrous wedges 
of the joint above. In this part of the plant the fibrous 
laminae, the medullary rays, and the cells of the cellular 
layers become intermingled in a remarkable way. At the 
base of each cellular lamina especially the fibres radiate 
from a common centre in an almost inexplicable manner. 
Agreeing with Mr. Carruthers and others in regarding 
Mr. Binney’s Calamite as Equisetaceous, Prof. Williamson 
pointed out that his specimens exhibited much stronger 
affinities with the true Conifera, though in their broad 
features, and in the general arrangement of their alternating 
series of tissues, they are essentially Calamites. Since Mr 
Binney’s specimens exhibit all the characteristics of M. Brong- 
niart’s genus Calamodendron, it is desirable that the name 
should be applied to them, whilst the coniferous affinities of 
the new type would be indicated by the institution of a new 
genus Calamopitus for its reception. The range in time 
of the two types is yet undetermined, but Calamodendron 
appears to be the prevalent form amongst the lower coal- 
measures of Lancashire, and Calamopitus is more common 
in the upper series. 
Professor Williamson called attention to the unsatis- 
factory state of our knowledge respecting the structure of 
the stems of Calamites prior to the investigation of Cala- 
mitea by M. Cotta, although M. Brongniart had long before 
possessed undescribed siliceous stems from Antim, but of 
which he never published the history. Subsequently, Dr. 
Dawson, of Canada, described certain Calamites in which 
