H5 
Catamites and Dicotyledons . 
3. The structures figured by Williamson apparently im- 
bedded in the supranodal wood of Calamites are not 
branches, as he originally stated, but, on the contrary, are 
leaf-traces, as subsequently suggested by Williamson and 
Scott. 
4. As a consequence of paragraphs 2 and 3, and other 
minor considerations, the writer’s earlier suggestion that the 
figures of tangential sections of the secondary wood of 
Calamites should be inverted is not to be accepted. 
5. Analogues of Williamson’s lenticular organs (infranodal 
canals) exist in certain palustrine Dicotyledons of the 
present day. 
The writer is under great obligations to Sir William 
Thiselton-Dyer and Dr. D. H. Scott for the hospitality of 
the Jodrell Laboratory at Kew, and to the latter for free 
access to his collection of fossil plants. Thanks are also due 
to Dr. Henry Woodward and Mr. Newton of the Museum 
of Natural History, South Kensington, for the opportunity of 
examining the large series of palaeobotanical sections in their 
charge. Last, but not least, he wishes to express his gratitude 
to M. Renault, of the Museum at the Jardin des Plantes, 
for very kindly permitting him to examine his preparations 
illustrative of Calamitean anatomy. 
L 
