154 Prof. W.C. Williamson. On the Organisation [Fob. 12, 



February 12, 1891. 

 Professor ALFRED NEWTON, M.A., Vice-President, in the Chair. 



The Right Hon. William Lawies Jackson was admitted into the 

 Society. 



The Presents received were laid on the table, and thanks ordei 

 for them. 



The following Papers were read : 



I. "On the Organisation of the Fossil Plants of the Cot 

 measures. Part XVIII." By W. C. WILLIAMSON, LL.D., 

 F.R.S., Professor of Botany in the Owens College, 

 Manchester. Received January 22, 1891. 



(Abstract.) 



On three preceding occasions the author has directed attention 

 the existence in the older Carboniferous rocks of a remarkable fc 

 of fructification which seemed to belong to the Calamarian family oi 

 plants, though presenting features distinct from any that had hither 

 been described. In the first instance, in 1871, he placed this fructi- 

 fication in Sternberg's provisional genus Volkmannia, under the name 

 of V. Dawsoni. Some small fragments of the same type, obtained 

 a later period by the late Professor Weiss, of Berlin, led him 

 identify the plant with Binney's hitherto very obscure gem 

 Botvmanites, an identification which is accepted by Professor Wil- 

 liamson. Still more recently, a number of additional specimens hav 

 been obtained from the Ganister Carboniferous beds of Lancashir 

 and Yorkshire, which not only throw further light upon the plant 

 but have made it possible to re-write its history in an almost complt 

 form. 



Like all the other Calamari, Bowmanites was a plant with a 

 tinctly articulated stem, each node of which bore a verticil of lat 

 appendages. In the vegetative organs each of these nodal appendage!' 

 consisted of a verticil of the linear, uninerved leaves characteristic of 

 the old, ill-defined genus Asterophyllites. In the fructification these 

 foliar verticils are replaced by a broad circular disk, the margin of 

 which sustained a verticil of leaf-like " disk-rays." These rays can 

 scarcely, at present, be identified with true leaves, since they have 



