332 



CALAMITES. 



[CH. 



elements (fig. 86, 2). At one point in the epidermis of 

 fig. 86, 1, there appears to be a stoma, but the details are 

 not very clearly shown (fig. 86, 4) ; the two cells, s, s, bordering 

 the small aperture are probably guard-cells. 



The nature of the assimilating tissue, the comparativelj 

 thick band of thin- walled cells with intercellular spaces, and^ 

 the exposed position of the stomata suggest that the plant 

 lived in a fairly damp climate; at least there is nothing to 

 indicate any adaptation to a dry climate. 



In the Binney collection of plants in the Woodwardif 

 Museum, Cambridge, there is a species of a very small shoo! 

 bearing three or four verticils of leaves which possess the same 

 structure as those of fig. 86. We may probably regard sucl 

 twigs as the slender terminal branches of Calamitean shoots. 



a. Calamocladus (Asterophyllites). 



The generic name Asterophyllites was proposed by Brongniart^ 

 in 1822 for a fossil previously named by Schlotheim^ 

 Gasuarinites, and afterwards transferred to Sternberg's genus 

 Annularia. In 1828 Brongniart^ gave the following diagnosis 

 of the fossils which he included under the genus Astero- 

 phyllites : — "Stems rarely simple, usually branched, with opposite 

 branches, which are always disposed in the same plane ; leaves 

 flat, more or less linear, pointed, traversed by a simple median 

 vein, free to the base." Lindley and Hutton described examples 

 of Brongniart's genus as species of Hippurites^, and other 

 authors adopted different names for specimens afterwards re- 

 ferred to Asterophyllites. 



At a later date Ettingshausen^ and other writers expressed 

 the view that the fossils which Brongniart regarded as a distinct 

 genus were the foliage -shoots of Calamites, and Ettingshausen 

 went so far as to include them in that genus. In view of the 

 generally expressed opinion as to the Calamitean nature of 

 Asterophyllites, Schimper^ proposed the convenient generic 



1 Brongniart (22), p. 235. 

 3 Brongniart (28), p. 159. 

 5 Ettingshausen (55). 



2 Schlotheim (20). 



4 Lindley and Hutton (31), PL cxc. 



6 Schimper (69), p. 323. 



