350 



CALAMITES. 



[CH. 



literature contains numerous illustrations and descriptions of 

 long and narrow strobili designated by different generic terms 

 such as Volkmawiia, Brukmannia, Calamostachys, Macro - 

 stachya and others ; many of these have since been recognised 

 as the cones of Calamites, while some species of Volkmannia 

 have been identified with Sphenophyllum stems. Before further 

 considering the general question of Calamite cones, a few 

 examples may be described in detail as types of fructification 

 which are known to have been borne by Calamites. The 

 examples selected are species of the two provisional genera 

 Calamostachys and Palaeostachya. 



The usual form of a Calamite cone is illustrated in fig. 93, 

 which represents a fertile shoot bearing a few narrow linear 

 leaves of the Calamocladus type ; in the axils of some of these 

 are borne the long strobili. 



Fig. 93. Calamostachys sp. A fertile Calamitean shoot. From a specimen in 

 the Geological Survey Museum, Jermyn Street, London. From the Upper 

 Coal-Measures of Monmouthshire (No. 5539). 



