320 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1918. 



large cones somewhat resembling- thos'e of Macrostachya bnt more 

 open and characterized by a disk-like protective flange pendent from 

 the bract whorls. Cingularia comprises long and lax cones with 

 widely spaced whorls of coherent bracts at right angles to the axis, 

 subtended by whorls of nonalternating sporangiophores, equal in 

 number to the bracts. The sporangiophores were lignlate and divided 

 distad and each division bore two large pendent sporangia. 



Fig. 9. — Types of Calamife fructifications. 



1. Palaeostachya elongata Presl (after Sehenk). 



2. Calamostachya jugleriana Schimper (after Goeppert). 



3a. Transverse section of cone of Calamostachya passing through a whorl of sporangiophores. 



3b. Median vertical section of Calamostachya. 



4. Diagrammatical median section of Huttonia. 



5a. Part of cone of Cingularia typlca (after Weiss). 



5b. Two sporangiophores of preceding seen from below. 



6. Palaeostachya vera, Diagrammatical median vertical section (after Hickling): 



vascular tissue black. 



scleritizcd parenchyma lined. 



soft parenchyma dotted. 

 On the left the section passes through a bundle and on (ho right between bundles. 



The final order of the Calamariae, the Equisetales, consists of the 

 single family, Equisetaeeae, and comprises at the present time the 

 single genus, Equisetum, with 25 to HO rather uniform, widely dis- 

 tributed, mostly small and chiefly temperate species of scouring 

 rushes or mare's tails. The cones are terminal on fertile shoots or 

 on branches from the vegetative shoots, and entirely lack sterile 

 bracts. They consist of peltate sporangiophores carrying from 5 



