from the Middle Coal Measures, near Rochdale. yy 



Tbracts which in most cases accompany them. The excep- 

 tion is the type known as Volktnannia Sternbg., which 

 Weiss defines as mostly small cylindrical spikes, in which 

 whorls of bracts alternate with whorls of sporangia. 



Now, in the Rochdale spike, as already intimated, it is 

 not certain that sporangiophores are altogether absent; 

 but at least it may be said that there are no sporangio- 

 phores comparable with those met with in all the 

 Calamarian spikes save Volhnannia. Hence, if the spike 

 is to be referred to any of the types enumerated, it can 

 only be to that of Volkmannia, as defined by Weiss, and 

 it is an interesting coincidence that in this type the 

 presence or absence of sporangiophores is not certainly 

 determined. 



But the mere fact of this uncertainty is itself sufficient 

 to suggest a doubt as to whether Weiss's Volkmannia is 

 properly placed when associated with the Calamariece, 

 because, in all other known spikes of that group, the 

 sporangiophores are more or less conspicuous structures, 

 and such as can hardly escape observation. Weiss 

 himself was alive to this, and pointed out that Volkmannia 

 might ultimately have to be associated with or merged in 

 the genus Sphenophyllum. This being so, we may now 

 turn to the spikes of Sphenophyllum, and see whether it is 

 possible to find among them a place for the Rochdale 

 specimen. 



The majority of the fruit-spikes of Sphenophylhim 

 described and figured in the literature are little more than 

 impressions like the one before us, and, so far as I know, 

 there is only one type whose internal structure can be said 

 to be known. This is the spike described by Williamson 

 in 1871,* and again in i874,t under the name of Volk- 

 mannia Dawsoni, and in 1890 and 1891 under that 



* Memoirs and Proceedings of the Manch. Lit. and Phil. Soc., Series III., 

 Vol. IV-.; \Phil. Trans., 1874. 



