FOSSIL VASCULAR CRYPTOGAMS 



127 



passes, and from the margin of which spring the linear-lanceolate free 

 portions of the leaves. Annularia has been regarded by some writers 

 as an herbaceous aquatic plant ; but there is little doubt that it is the 

 branches and foliage of Calamites. 



The fructification of the Calamarieae, described under the name 

 Calamostachys with which must be identified Volkmannia (Stbg.) and 



FIG. 98. Leaves of Calamitina. 

 (After Weiss.) 



\ 



FIG. 99. ArchiPOcalamites radiatus Stur 

 (After Stur.) 



Bruckmannia (Stbg.) has not unfrequently been found in organic con- 

 nection with the stem. Each cylindrical cone-like fructification consists 

 of a number of whorls of sporophylls, but differs from that of Equisetum 

 or of Equisetites in the fertile whorls alternating, in each spike, with 

 barren whorls consisting of a large number of lanceolate acute leaves, 

 free or more or less connate at the base ; the free portions completely 

 cover the next upper fertile whorl and the base of the barren whorl 



