Geology and Mineralogy. 



layers of coal apparently composed of thei 



" 'e way from the Middle Devonian 



But thev are invariablv found as .1 



ey range all the way from the M: 



nd their broad 

 lerely herbaceo 



developed than that of the Psllophytoi 

 M.<;ra I ,d-e„ry .vve.-es all this. He a< 

 he impossible here eve 

 of these planl 



i Dadoxylon, though in t 

 are divisible into sevc 

 •daites, Eu-cordaites, s 



been very extensive, and his conclusions deserve careful - 

 . though one can hardly help so* 



united to the ordinary Cordaites plants of mu 



The Calamodendra, whose structure was first mad. 

 C "tta, a, ,1 vv -lii,-h l,. lV< ]. ir , !} ]„.,„, .,, U ,1I illustrated '■;. 

 Sul Uar here elevated into I'lanuly, which iucludes^tln m 

 ;'. /; ' /">'W and ( ,il <„,,„! ,,,! o//.' agreeing in having an 



„rra/„ od,Hd,y, r -< 

 alternate radiating plates of libers without definite <> 

 others in radiating series. The leaves of th- - 



'•.': ! '<i founded with th-.seo! lefn- r >/ 'it**, and i 



ngidandverri-illale. Williamson ha< shown that L'<d>, : 

 hinueya.u, and a species ,,f V»lkm<mnia\w 

 <>' in,,,,!,,., V - , and Arthr<> t ,;t> s 



Po^to 



The concluding plates of the men 



" [ rh <- principal arbor, .■•out plants of the Coal tor 

 are all highh sugg .... , m\ of them fully 



