THE CARBONIFEROUS FLORA, 



123 



late branchlefcs, or on the lower part of the stem the 

 marks of the attachment of the roots. The Calamites 

 grew in dense clumps, budding off from one another, 

 sometimes at different levels, as the mud or sand accumu- 

 lated about tlieir stems, and in some 

 species there were creeping rliizomata 

 or root-stocks (Figs. 46 to 49). 



But all Calamites were not alike 

 in structure. In a recent paper* 



V 



I 



V. 



Fig. 46. — Calamites. 

 A, C. Suckoril. B, 

 C. Cistii. ( From 

 " Acadian Geolo- 

 gy-") ^' , 



Fio. 47.— .Erect Cala- 

 mites, witli roots at- 

 tached (Nova Sco- 

 tia). 



Fig. 48.— Node of C. 

 Cistii, with long 

 leaves (Nova Sco- 

 tlft), , 



Dr. Williaiuson describes three distinct structural types. 

 What he regards as typical Calamites has in its woody 

 zone wedges of barred vessels, with thick bands of cel- 

 lular tissue separating tliem. A second type, which 



* " Memoirs of the Philosophical Society," Manchester, ISSS-'S?. 



