Plate XII. 



GREAT TDBES OF DABMONELIX. 

 Fig. 1.— A piece of transverse trunk or "rhizome." with the leaser tubes and tubules cut 



away, showinK the great tubes within. Lett rhizome of Fig. 10. 

 Fig 2 —View of great tubes reduced about one-third, lesser tubules cut away. 

 Fig. 3.— One of the greater tubes, natural size, showing hoUowness, thickness of wall, 



bnrk-like structure, and hollow branch. 

 Fig. 4.— Cross-section from the great tube, seen in Fig. 2. 

 Fig. 5.— Same, tangential section. 



[From a specimen in the Morrill Geological Collection, State Museum.] 



