A TYPE OF PALAEOZOIC PLANTS. 407 



identical in the two genera". 1 In Catamites the leaves were 

 separate ; in Equisetum they cohere to form a sheath ; in 

 both genera the position of the branches is the same. In 

 Catamites the vascular bundles do not always alternate at 

 the nodes as in Equisetum, but in their collateral form, and 

 in the character of their elements, the vascular tissue of the 

 two plants is in close agreement. As regards the fructifi- 

 cation, one important fact to notice is the occurrence of a 

 heterosporous form of Calamostachys (C Casheana Will.) ; 

 this agrees closely with C. Binneyana Schimp, and must 

 probably be included with that species as a calamitean 

 strobilus, differing chiefly in the possession of macrospores 

 and microspores from the cone of a recent Equisetum. 



It is unfortunate that we are without any information as 

 to the structure of the numerous equisetaceous stems which 

 reached such a large size in the Triassic period ; and in the 

 later Jurassic and Wealden rocks still surpassed in the 

 breadth of stem our present representatives of this ancient 

 genus. Without further knowledge of the fossil Equisetites, 

 we cannot hope to completely fill up the lacunae in the 

 records of equisetaceous and calamarian development. 



In his later memoirs on Carboniferous plants Professor 

 Williamson made it a rule, in the explanation of plates, to 

 add the number of the page on which each figure was 

 referred to. It would be a great convenience if this custom 

 were continued in the " Further Observations on the Or- 

 ganisation of the Fossil Plants of the Coal Measures," in 

 which new series we may hope to have a succession of 

 memoirs of the highest importance to botanical science. 



BIBLIOGRAPHY. 



BlNNEV, E. W. Observations on the Structure of Fossil Plants 

 found in the Carboniferous Strata. Part i., Catamites and 

 Calamodendron. Palaeontographical Society, 1868. 



CARRUTHERS, W. On the Structure of the Fruit of Calamites. 

 Journ. Bot., vol. v., p. 349, 1867. 



Hick, T. (i) Calamostachys Binneyana Schimp. Proc. Yorks. 

 Geol. Polyt. Soc., vol. xii., pt. iv., 1893. 



1 Williamson and Scott, p. S69. 



