402 



SPHENOPHYLLUM. 



[CH. 



particular species of stem. The genus Calamostachys affords 

 an example of a name which is intended to denote that a cone 

 so called helongs to a Calamarian plant ; similarly such a name 

 as Sphenophyllostachys may be used for Sphenophylloid cones 

 which cannot be connected with certainty to particular species 

 of Sphenophyllum. It has been suggested that the genus 

 Bowmanites, first used for a cone which was afterwards recog- 

 nised as belonging to a Sphenophyllum, should be employed 

 instead of the sesquipedalian term Sphenophyllostachys. The 

 latter is used here as being in accordance with a generally 

 accepted and convenient system of nomenclature, and as a 

 name which at once denotes the fact that the fossil is not only 

 a cone but that it belongs to a Sphenophyllum. 



Sphenophyllostachys Dawsoni (Will.). Figs. 107, A and G, 108. 

 Probably the strobilus of Sphenophyllum euneifolium (Sternb.). 



Fig. 108. Diagrammatic longitudinal section of a Sphenophylluvi strobilus. 

 The upper figure represents a portion of a whorl of bracts. (The smaller 

 figure, after Zeiller.) 



The cone consists of a central axis bearing a number of 

 verticils of bracts coherent in their lower portions in the form 



