I^] EQUISETITES HEMINGWAYI. 263 



genus Bornia (Archaeocalamites), which also exhibit the Equi- 

 setum-like character; the axis bears sporophylls only and no 

 sterile bracts. It would appear then that in the Palaeozoic 

 period the Equisetaceous strobilus, as we know it in Equisetum, 

 was represented in some of the members of the Equisetales. 



1. Equisetites Hemingwayi Kidst. Fig. 57, J.. 



Mr Kidston^ founded this species on a few specimens of 

 cones found in the Middle Coal-Measures of Barnsley in 

 Yorkshire. The best example of the cone described by Kidston 

 has a length of 2-5 cm., and a breadth of I'S cm. ; the surface 

 is divided up into several hexagonal areas 4 mm. high and 

 5 mm. wide. Each of these plates shows a fairly prominent 

 projecting point in its centre ; this is regarded as the point of 

 attachment of the sporangiophore axis which expanded distally 

 into a hexagonal plate bearing sporangia. An examination of 

 Mr Kidston's specimens enabled me to recognise the close 

 resemblance which he insists on between the fossils and such 

 a recent Equisetaceous strobilus as that of Equisetum limosum 

 Sm. Nothing is known of the structure of the fossils beyond 

 the character of the superficial pattern of the impressions, and 

 it is impossible to speak with absolute confidence as to their 

 nature. The author of the species makes use of the generic 

 name Equisetum; but in view of our ignorance of structural 

 features it is better to adopt the more usual term Equisetites. 



Since Kidston's description was published I noticed a 

 specimen in the British Museum collection which throws some 

 further light on this doubtful fossil. Part of this specimen is 

 shown in fig. 57, A. The stem is 21 cm. in length and about 

 5 mm. broad ; it is divided into distinct nodes and internodes ; 

 the former being a little exaggerated in the drawing. The 

 surface is marked by fine and irregular striations, and in one 

 or two places there occur broken pieces of narrow linear leaves 

 in the neighbourhood of a node. Portions of four cones occur- 

 ring in contact with the stem, appear to be sessile on the nodes, 



1 Kidston (92). 



